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tcj_21 1985-1112

1. Subscripted variables with up to 127 dimensions Means for declaring array constants together with array operations and conditional constructs make defining large problems quick and easy Input and output statements Several file formats are supported in cluding the ubiquitous DIF format already used by dozens of commercial packages Automatic dimensioning input until end of data together with the conditional forms mentioned above make possible size independent matrix generators perfect for imbedded ap plications Report statements which allow the user to include values in the final report that can be computed from the Solution This not only eliminates the need for additional constraints it allows the display of nonlinear fun ctions of the solution values Linear Optimizer with its high level matrix generator language makes it possible to create special applications that require no knowledge of linear programming by the user Like spread sheet templates and data base ap plications Linear Optimizer models add the essential elements to a useful powerful package programmability and integration Linear Optimizer is available for PC DOS 2 0 PC DOS 3 09 or CP M 2 29 systems for 400 To order or to request more information contact Stephen Vestal at The Acme Computer Company Box 51193 Seattle WA 98115 phone 206 522 6655 Programmable Microconrtoller Basicon now offers a 3 x 4 fully progra
2. position open This disconnects the memory board data and ad dress lines from the program memory connects the CPU ad dress and data lines to the program memory and removes the ground from the reset pin on the CPU This is accomplished in exactly the reverse order as going from the run mode to the examine mode in the explanation above PSEN is the program memory read pulse which inputs instructions to the CPU PSEN enters the memory board via pin 24 of the interface socket and goes to the CS input of the memory ICs This pulse is active LO Also a capacitor and resistor circuit is connec ted to the reset pin on the CPU to cause a small time delay when going from the examine mode to the run mode This is necessary to ensure that the address bus multiplexer outputs from the CPU are completely enabled before the CPU begins executing instructions In the CD 1 Program Memory Board design see Figure 15 2114 memory ICs were used These ICs are 1K by 4 bit memories and by utilizing two 37 2114 s 1K of program memory was ob tained If you need more than 1K of program memory you can use different memory ICs or add additional 2114 s and decode the higher order address bits to enable the appropriate 1K block The 8035 has the capability of accessing up to 4K bytes of program memory Once a program has been written and debugged using the CD 1 program memory board the same program can be written into a 2716 5 vol
3. With these tools you can really program S C Macro Assembler Version 2 0 is the latest in a long line of enhancements to the oldest commercially available assembler for Apple computers Supports the full instruction set and all addressing modes of the 6502 65C02 65802 and 65816 processors as well as Steve Wozniak s SWEET 16 pseudo processor Compatible with any Apple II II Plus e or c having at least 64K RAM and one disk drive S C Macro Assembler is well known for ease of use and powerful features rated number one by The Book of Apple Software You get an integrated editor assembler with over 29 commands and over 20 directives including macros conditional assembly global search replace edit and more Thousands of users in over 30 countries and in every type of industry attest to its speed dependability and user friendliness S C Macro Assembler blends power simplicity and performance to provide the optimum capabilities for both beginning and professional programmers Both DOS 3 3 and ProDOS versions are available now 100 each you can save by getting both together for only 120 Upgrades are available for owners of previous versions Disks are not copy protected so you can easily make back up copies Cross Assembler Modules Owners of the S C Macro Assembler may add the ability to develop programs for other systems We have modules for most of the popular microprocessors priced from 32 50 to 50 each Motor
4. INCA Increment A DECA Decrement A CLRA Clear A CPLA Complement A DAA Decimai adjust A SWAP A Swap nibbles of A RLA Rotate A lett RLCA Rotate A iett through carry RRA Rotate A nght RRCA Rotate A ngnt through carry Input Output Mnemonic Description INA P Input port to A OUTL P A Output A to port ANL P data And immediate to port ORL P data Or immediate to port INS A BUS input BUS to A OUTL BUS A Output A to BUS AN BUS data And immediate to BUS ORL BUS data Or immediate to BUS MOVO A P input expander port to MOVDP A Output A to expander port ANLD P A And A to expander port ORLOP A Or A to expander port Mnemonic Deecription Bytes Cycios JMP addr Jump unconditional JMPP QA Jurnp indirect DJNZ A addr Decrement register and skip JC agar Jump on carry 1 JNC addr Jump on carry 0 JZ addr Jump on A zero JNZ addr Jump on A not zero JTO addr Jump on TO 1 JNTO addr Jump on TO 0 JT1 addr Jump on T1 1 JNT1 addr Jump en T1 0 JFO addr Jump on FO 1 JF addr Jump on Ft 1 JTF addr Jump on timer flag JNI addr Jump on INT 0 JBb addr Jump on accumulator Hi Subroutine Mnemonic Description CALL addr Jump to subroutine RET Return RETR Return and restore status Description Ciear carry Complement carry Clear flag 0 Complement tiag 0 Clear flag 1 Complement tiag 1 NN N nenen NNN NY NNYNNRYNY YN NNN The Computer Journal Issue 21 C1 10 mF electr
5. local electronics manufacturer may also be a source be sure to ask if you can take any apparen tly discarded boards Some surplus electronics outlets sell scrap boards people buy them to experiment with or to salvage parts off them Remember that just like functioning boards scrap boards come in different types and present a variety of unsoldering challenges Look in the back of electronics magazines for the names of surplus fir ms Below is a firm that currently hasa limited supply of boards with relays and other parts that are sold as salvageable John J Meshna Jr Inc PO Box 62 E Lynn MA 01904 617 696 2275 Cat No SP 88A has one relay and lots of parts for 2 00 SP 88 2 two relays and parts 2 00 SP 88 3 three relays for 3 00 etc They do have a 15 minimum order so you may wish to get their catalog No SP 36 and see all the weird stuff they sell For a good catalog of unsoldering tools Edlie Electronics 2700 Hem pstead Turnpike Levittown NY 11756 800 645 4722 A short form catalog of soldering and desoldering tools is available by writing to Customer Service OK In dustries 3455 Conner St Bronx NY 10475 M The Computer Journal Issue 21 Build the Circuit Designer 1 MPB Part 2 Programming the Single Board Computer by Neil Bungard Introduction In the last issue of The Computer Journal we looked at Part 1 of an article describing the Circuit Designer 1 MPB CD 1 MPB In tha
6. perature change and the amount of current that is consumed in the process no longer requires a special testing booth and dedicated equipment It requires less attention from technicians can be done on the factory floor and saves a considerable amount of energy The first system is working so well that a second is being developed to run concurrently third Com modore 64 is used to process the test data in the DP department 4 A graduate student at the Univer sity of Southern California is using an ADC and a Macintosh computer in con junction with a spectrofluorometer and spectrophotometer to investigate the optical properties of marine phytoplankton in the Arctic Ocean Samples of natural populations of marine phytoplankton are filtered and then placed in the spectrofluorometer or spectrophotometer for measuremen 21 ts of fluorescence excitation and spec tral absortion The output is directed to the Macintosh through the ADC and has the advantage of allowing real time display of the data rapid processing and graphical representation 5 A former pharmacist now a quadraplegic confined to a wheel chair uses an ADC with an IBM PC and Keytronics 5152 Voice Actuated keyboard to control and monitor his environment He uses the BSR X 10 transmitter feature of the ADC to con trol lights and appliances in response to voice commands that he gives to his computer This is an early start for him soon he ll be able to
7. use ADCs are available These devices take care of the details of interfacing a computer to the Real World such that a programmer can concentrate on writing code to solve the problem at hand He doesn t have to become expert at digital electronics Another Peripheral ADCs come in various packages Some are printed circuit cards designed to plug into a bus slot of a par ticular computer Others are external devices that look a lot like a modem Because the internal variety link direc tly with the data bus of the computer they often provide faster operating speeds than external models External ADCs usually communicate with the computer via the RS 232 C serial interface One advantage to such a device is that it can be located close to the sensors being read often hundreds of feet away from the computer as the length of certain kinds of sensor leads can be critical Another advantage is that the external ADC won t require a particular computer to operate it Communicating with standard ASCII characters it ll work with the computer at home the one at the office or lab or the new one you get next year Regardless of its type of mounting ADCs can be intelligent or operate ac cording to discrete fixed logic Models i5 NGS FORTH A FAST FORTH OPTIMIZED FOR THE IBM PERSONAL COMPUTER AND MS DOS COMPATIBLES STANDARD FEATURES INCLUDE 679 STANDARD eDIRECT I O ACCESS eFULL ACCESS TO MS DOS FILES AND FUNCTIO
8. 2040 2686 2685 2698 2700 2718 2715 2728 2746 2756 2768 2776 2788 2798 2800 END K i SENSOR 5 INTON EXIT TASK 6 IF CHANNEL 6 THEN 2219 INTOFF WSELECT CURSOR 19 3 PRINT gt gt READING gt gt 3 QUT 4 5 IF BAND INP 6 1 THEN 2838 CHARIN INP 4 OUT 4 161 IF BAND INP 6 1 8 THEN 2968 HBYTE INP 4 IF BAND HBYTE 128 THEN 2956 QUT 4 145 IF BANDCINP 6 1 8 THEN 2186 LBYTE INP 4 HMASK BANDIHBYTE 15 RESULT LBYTE 256 HMASK sve eee eee E E y 5 IF BOND HBYTE 16 THEN RESULT RESULT PRINT CURSOR 19 66 FPRINT I5 2 RESULT K 1 SENSOR 6 INTON EXIT gt TASK 7 IF CHANNEL 7 8 THEN 2496 INTOFF WSELECT CURSOR 21 3 PRINT gt gt READING gt gt 5 OUT 4 6 IF BANDLINP 6 1 THEN 2318 CHARIN INP 4 OUT 4 161 IF BAND INP 6 1 THEN 2348 HBYTE INP 4 IF BAND HBYTE 128 THEN 2338 OUT 4 145 IF BAND INP A 1 THEN 2388 LBYTE INP 4 HMASK BAND GBYTE 15 RESULT e LBYTE 256 HMASK wee weve es 9 ov os IF BAND HBYTE 16 THEN RESULT RESULT CURSOR 21 3 PRINT t CURSOR 21 66 FPRINT IS 2 RESULT K e 1 SENSOR 7 INTON EXIT TASK 8 INTOFF WSELECT OUT 34 15 OUT 32 9 YEAR CONVERT INP 36 QUT 32 7 MONTH CONVERT INP 36 OUT 32 6 DAY CONVERT INP 36 OUT 32 4 HOUR CONVERT INP 34 OUT 32 3 MINUT
9. An ongoing project of mine is putting Forth in ROM and I have some infor mation on doing that It didn t take me long to understand Forth although learning all the words may take forever but seeing how it works in real code took some investigation Now I haven t figured everything out yet but the way it is put together is quite nice It reminds me of an article I published in my local club s newsletter about writing your own language The idea was that a good macro assembler could be used to create enough macros to do all your functions Writing a program would involve calling only macros and no actual code Forth is similar to that idea with some other features and of course the threading is different I will leave threading for a later date but point out some important thoughts now From what I have read about Moore the author of Forth it would appear that he based the design of the language on an HP calculator What he did was to create a processor architec ture in software The original work was done on big mainframes and all his early calculations were probably being done by hand on an RPN calculator Reverse Polish Notation machine My biggest problem with Forth is the RPN logic which is a carry over from the early calculators The idea however of making a processor in software is pret ty terrific as it can be transported to any physical system The actual codes to create the basics of the design stacks and m
10. BASIC well actually it looks an awful lot like a FORTRAN format statement is at line 510 where it starts out FPRINT This is a formatted print statement and takes the place of PRINT USING In this line the X values refer to blanks the I values to integers the S values to strings and the Z at the end passes a carriage return With the Z at the end the statement is like a Pascal WRITELN procedure without the Z it s like a Pascal WRITE procedure and doesn t move to the next screen line automatically The format string is followed by the variable list to be printed in this case the channel number a label to identify the input and the number of tics assigned to it for timing purposes When all seven channels have been thus identified or labeled as unselec ted by line 500 the program is ready to begin executing Task 0 the main logic contains the RUN statements that determine when each of the other tasks will be executed These RUN statements include the task number and the number of tics to use The tics can be supplied as an in teger constant or as a simple variable but NOT as a subscripted variable array For convenience the loop at 310 360 inputs the tic assignments as the array TKS I but these have to be converted one at a time into the simple variables TIKS1 through TIKS7 at 364 365 Note that MTBASIC is not at all tolerant of variable names that start out the same as reserved words like TICS
11. Inc of Seattle This is a popular ADC system and the one most familiar to the author but it is not at all difficult to substitute channel reading instructions for an ADC from another manufacturer In each program the code used to acquire analog data is identified as to its fun ction In Program Two the first seven tasks look very much the same but each has its own unique values making it necessary to repeat a similar routine seven times to read seven channels in dependently Program One HISPEED PAS Two characteristics of data acquisition and control systems that are often important to the user are a the rate at which analog data can be acquired and b the effective resolution available Both of these parameters are easy to measure with a computer program designed to read the ADC HISPEED starts with FUNCTION ACD which converts BCD binary coded decimal values from a clock card into ASCII decimal representation for display on the computer screen and for manipulation as decimal values by the program This program was written to Model Manufacturer Features Cost Model Manufacturer Features Cost Model Manufacturer Features Cost Model Manufacturer Features Price 23 Vendor List ADC 1 Data Acquisition amp Control System Remote Measurement Systems Inc 2633 Eastlake Ave E Suite 2986 Seattle WA 98162 266 DATA 255 16 Analog inputs of 12 bit resolution plus s
12. Real SampleMean SampleSum SumOfSquares SampleMeanSquared StandardDeviation Real Count Times Integer Integer Function ACD X Byte Bytes t Converts BCD byte into standard ASCII coded decimal representation Begin ACD X Div 16 10 X 16 X Div 16 5 Endi Procedure GetTime X Str Var Minute Second Hundr Sec 5 String 41 Hun Stringt211 Integers Begin Port 34 im 154 Port t32 34 Minute te ACD PortC 361 Port 32 28 Second Minute 609 ACD Portt 362 14 Str Second Sec Poctt3221 14 Hundr te ACDIPOort 36195 Str Hundr Hun Time im Sec Huns Ends Function GetData Charout Byte Bytes Const StatusPort 64 t these values computer specific SerialPort 44 Mask 1 Var Status Byte Begin Port SerialPort Charouts Repeat Status Port StatusPort 3s 4 read value from status port Until Status and Mask lt gt 8 check for full byte received Getdata PorttSerialPort21j read value from serial port Ends Function Analoginichennel Byte Integer VAR HighByte LowByte MaskedHighByte Byte Value Integer Begin Value GetData Channel 1 j Repeat HighByte GetData 161 1 Until tHighByte and 128 3 checks for digitizing done LowByte 9 GetData 145 MaskedHighByte e HighByte and 15 mask off needed bits Value LowByte 256 MaskedHighByte combine for 12 bit value
13. f DATA A A MEMORY 5 oU 4 4 DATA TAI Ye gt P25 P2 To System Event KO WR PSEN DB DB N Clock Output Counter Input o 7 ALE The Computer Journal Issue 21 to an address or data bit the bit must be grounded by closing its corresponding DIP switch 4 Examining the contents of the memory locations is accomplished with S1 in the examine position closed and S2 not depressed open In this configuration the memory ICs will be in the read mode and the contents of the memory location set on the address DIP switches will be reflected on the memory board displays Programming is accomplished by setting the address and data DIP switches to the desired values and depressing the deposit switch S2 This writes the data into the selec ted memory location which is ac complished by simultaneously enabling pin 1 of IC3 74LS373 and pulling pin 10 LO on the memory ICs When the deposit switch is released the change will be reflected by the memory board displays 5 After all the instructions have been entered into memory the program is executed by placing the run examine switch in the run TM E x KAYPRO users can share the advantage to LAT Just take off your main KAYPRO board and put LATI K into your cabinet All advantage of LATI is yours now CP M plus is registered trademark of Digital Research inc 280 i5 a registered trademark of Zilog inc Turbo Dos is a registered trademark of Software 2000 inc
14. formula where U equals the degree of difficulty P equals the number of pins to be unsoldered thus we have U P or to express it in literal terms the more pins or leads a given part has the more difficult it will be to successfully NEW FREE CATALOG Engineering Protessional Software Figure 4 Using a m knife point to lift up a staked IC pin while oes LOCIPRO Root Locus 69 95 ACTFIL Active Filter Design Analysis 69 95 STAP Static Thermal Analysis 69 95 MATRIX MAGIC Matrix Manipulation 69 95 RIGHTWRITER Proofreader amp Writing Style Analyzer 74 95 ACNAP2 AC Circuit Analysis 69 95 DCNAP DC Circuit Analysis 69 95 SPP Signal System Analysis 69 95 PLOTPRO Scientific Graph Printing 69 95 PCPLOT2 High Resolution Graphics 69 95 2200 Business Way Suite 207 Riversige CA 92501 e 714 781 0252 unsolder it without damaging the part or the board Actually this theory is not my own invention and you may have seen it ex pressed before but in its inverse form Some kits or articles will tell you that the best way to unsolder something such as a 16 pin IC DIP is to use a small nippers and cut all the leads freeing the IC from the board then unsolder each individual pin Naturally this works quite well from the boards per spective but leaves a useless I C This is where the art comes into play If an I C is defective
15. number time and date stamps must accompany the RESULT into the disk record interrupts are turned off at the beginning of the task and back on at the end Line 2740 checks to see whether a channel read has been done In other words if K is a 0 nothing is done If K has been turned on by one of the other tasks then the record is written The FILE 1 statement at 2750 determines which open file is used here we re only using one After the FILE 1 statement the FPRINT statement or any regular PRINT statement will output to the file not the CRT screen The FILE 0 statement that follows will cause subsequent PRINTs to go to the CRT until a file is specified again Finally the flag K is cleared and we re done Final Notes On MTBASIC MTBASIC provides many useful features that endear it to the heart of anyone who likes to write good readable code Its one significant drawback I feel is the way redundant spaces are stripped from a program with the SAVE command The apostrophe single quote can be used to define a REM statement as you see here but beware of the SAVE com mand The compiler won t object to the neat spacing that you provide to make your source readable but if you SAVE a program from MTBASIC those spaces will be gone MTBASIC up to the version I have does not contain any kind of editor not even a line editor like MBASIC You CAN replace a line by re typing it and small errors can be corrected this wa
16. possible over a bar no pole or other mechanical device can be used The premier American in this event is Dwight Stone and if you saw him during the 84 Summer Games you would have seen him standing in front of the bar for some time deep in thought He was not pysching himself up rather he was mentally rehearsing the jump thinking through every move in his mind before actually doing it In many ways unsoldering demands the same mental preparation if it is to be successful Also like the games success is not assured Dwight Stone did not win the gold medal but he did compete Here is a simple checklist for un soldering 1 Decide what is the most important goal Don t try to save a 50 cent IC only to damage an expensive board 2 Have a plan that is what tool or method will be used 3 Be prepared to change the plan if it isn t working 4 If you retrying a method for the first time then practice on a scrap item The Computer Journal Issue 21 5 Remember nothing works all the time and everything can be fixed look for the next article in this series Sources To say that we ve only scratched the surface of the art of unsoldering is to put it mildly Clearly the key to reliably practicing this art is to practice it But not on the motherboard of a two thousand dollar computer use a scrap board Where can you get scrap boar ds Check with the local TV or Stereo repair place they may be throwing them away
17. remove solder from each lead as described above About half the time the part will fall right out and half the time it won t Wiggle it this should break any weak remaining solder bond and then the part will come out If it wiggles freely but still won t come out check for solder blobs at the end of each lead to remove any just wipe the iron across the lead most of the solder will adhere to the iron and leave a smooth lead for really stubborn blobs use solder wick Check for any residual solder on the top side of the board Rarely the part still won t pull out this is usually because the part was tightly fitted originally and friction is holding in it just keep prying at it firmly but cautiously Unsoldering A Dip The vast majority of digital IC s come in DIP packages the word DIP is an acronym for dual in line pins the smallest has eight pins four to a side the largest 64 pins 32 on each side Parts with two or three leads are easy to unsolder and even if damaged in the process most are readily available and inexpensive IC s fall into a middle ground since some are as common as resistors others harder to find and some almost impossible to replace and the number of pins is irrelevant in this regard There are companies that make a living by recovering out of production IC s from circuit boards testing them and re selling to those who still need them for repairs etc Those firms don t care what happens to the board
18. supply companies because the width is important You want to use a wick that is as wide as the solder fillet you re trying to unsolder Too narrow a wick won t absorb all the solder too wide a wick risks damage to traces from the extra heat it holds The width sold by Radio Shack is a good all around size but if it s too wide for a small joint then DIP IC hole trim the end a little The wicking action is not as vigorous with solder as with other liquids thus sometimes you may find that solder will remain in the circuit hole or on the op posite side of the board especially double sided boards This can also hap pen when using a solder sucker although a good spring loaded type will tend to preclude this No problem though just apply the wick on the top side being careful not to let the side of the iron char components Many times a stubborn joint will respond to the use of a desoldering tool followed up by solder wick 11 Figure 2 Solder wick being used to clear residual solder from a Occasionally you will create a solder bridge between two traces these rascals are very insidious causing many problems not the least of which is how to correct them once you identify the culprit The old method involved using a cleaned iron which is then placed over the solder bridge causing the solder to creep up the iron by capillary action thus removing the bridge That sounds much better than it actually works it req
19. tables center distance factor tables design based on horsepower or allowable torque Section 8 Shafts and bearings Deter mination of stresses for solid shafts sizing porous metal bearings non metalic bearings ball bearings bearing loads tolerances and clearances Section 9 Vibration and shock isolation Fundamentals of vibration vibration analysis vibration mounts Section 10 Introduction to robots Manipulator geometry joints degrees of freedom yaw pitch and roll dimen sions of a link geometric con figurations load capacity Manipulator motion manipulator components ap plications This data book does not cover the subjects as extensively as an Engineering manual but it would take a shelf full of books to cover this wide range of information It is very useful for the computerist who needs a quick source of information on sizes fits gears center distances strength and other information M The Computer Journal Issue 421 Unsoldering fcontinued from page 18 technicians who are intimately familiar with the product Confronted with a bad board they often zero in on the of fending chip with just a few simple tests Rarely do they need to unsolder more than one or two IC s before they cure the malfunction Anyone who has repaired many boards can confirm this fact because a few very enlightened vendors will include the troubleshooting steps in the documen tation and by following that data you
20. tainly was I should explain that analog digital conversion provides a way for any computer to talk with the rest of the world the Real World that exists outside the computer There are analog digital data acquisition and con trol systems whew let s call them ADCs from now on available from a number of companies that not only let the computer MONITOR its environ ment but allow it to CONTROL its en vironment as well These ADCs provide digital con trolled outputs that can be used to operate relays or indicators and some even come with a transmitter to operate the familiar BSR X 10 series of AC line carrier remote control modules These are the modules available at Radio Shack stores and elsewhere that are turned on or off by radio frequency signals sent over the AC lines Once a computer can operate BSR modules a programmer can easily design a sophisticated home control and energy management program using con venient wireless remote control Most comuters that we know of today are DIGITAL computers They respond to electrical impulses that are either there or they aren t Bits in our computers are either ON or OFF By bunching those bits into bytes and wor ds we can express larger digital values but information in a computer can all be traced back to those two values ON or OFF Most of the important infor mation in our environment comes in ANALOG form it varies continuously along a scale o
21. LINP O 1 THEN 998 HBYTE INP 4 IF BAND IHBYTE 128 THEN 998 OUT 4 145 IF BANDCINP 6 1 THEN 1836 LBYTE INP 4 HMASK BANO HBYTE 15 RESULT LBYTE 256 HMASK IF BANDIHBYTE 16 THEN RESULT RESULT CURSOR 11 3 PRINT CURSOR 11 66 FPRINT 15 2 RESULT K 1 SENSOR 2 INTON EXIT TASK I IF CHANMEL 3 THEN 1398 INTOFF WSELECT 8 CURSOR 135 3 PRINT gt gt READING gt gt 5 OUT 4 2 IF BAND INP 6 1 9 THEN 1229 CHARIN INP 4 OUT 4 161 IF BANDCINP 6 1 THEN 1259 MBYTE INP 4 IF BANDIHBYTE 126 THEN 1248 QUT 4 145 IF BAND INP 6 1 6 THEN 1299 LBYTE IMP 4 HMASK BAND HBYTE 15 RESULT LBYTE 256 NNASK SELECT ORIGINAL WINDOW SET CURSOR TO PRINT MSS PRINT READING MESSAGE START A D ON CHANNEL 2 WAIT FOR REPLY FROM ADC 1 GET UNUBED REPLY ASK FOR HIGH BYTE OF DATA WAIT FOR REPLY GET HIGH BYTE OF DATA NOT FINISHED A D VET ASK FOR LOW BYTE OF DATA WAIT UNTIL RECEIVED GET LOW BYTE OF DATA MASK FOR 4 DATA BITS USED COMBINE INTO TOTAL VALUE CHECK NEGATIVE FLAG SET CURSOR TO ERASE MSG ERASE READING MESSAGE SET CURSOR TO PRINT VALUE PRINT VALUE READ DATA TO DISK FLAG INTERRUPTS BACK ON END OF TASK 2 DEFINE BEGINNING OF TASK 3 SKIP IF CHANNEL NOT SELECTED INTERRUPTS OFF SELECT ORIGINAL WINDOW SET CURSOR TO PRINT MSS PRINT READING MESSAGE START A D O
22. M plus e og Kinder s in OEM quantity plus system BIOS source code available DRI CP M plus manual 50 New word word processor program for MSC ICO ADD 50 e Completely faster than other Z80SBC MSC HCS S99 Expansion card tor ICO RAM disk upto 2M byte and SCSI hard disk interface card for ICO with instailation program USA distributer SOUTHERN PACIFIC COMPUTER PROOCTS U S A INC P O BOX 4427 Berkeley CA 94704 0427 U S A Phone 415 253 1270 Dealer and distributer inquiries welcome Denmark Danbit 03 662020 Finland BB Soft 90 692 6297 india Betamatix PVT Ltd 0812 71989 Sanwa Bidg 2 16 20 Minamisaiwai Nishi Yokohama JAPAN 220 Phone 045 314 9514 Telex 3822320 SPACIF J Advanced single board computer technology company 0 OUT 7 i mami oz a o Socket E LI on 0 IN 7 Amuomol ooz Ag Ay 09 97 Au Ag Po 7 7 7 Piz Socket A Socket B INTERFACE SOCKETS The Computer Journal Issue 21 7 1ACK 0 9 INT i Socket C This is a diagram of the pin assignment and placement for the interface sockets A0 through A11 multiplexed address bus outputs D0 through D7 data bus interface bidirectional P10 through P17 170 port 1 interface quazibidirectional INT 0 through 7 priority interrupt request inputs active lo IACK 0 through T interrupt acknowledge outputs active lo AMOD address multiplexer o
23. System Generation Volume 2 Number 4 issue 8 Build a VIC 20 EPROM Programmer Multi user CP Net Build a High Resolution S 100 Graphics Board Part Three Construction System Integration Part Three CPIM 3 0 e Linear Optimization with Micros LSTTL Reference Chart Volume 2 Number 5 Issue 9 e Threaded interpretive Language Part One Introduction and Elementary Routines e Intertacing Tips and Troubles DC to DC Converters Multi user C NET Reading PCDOS Diskettes with the Morrow Micro Decision LSTTL Reference Chart DOS Wars e Build a Code Photoreader Volume 2 Number 6 issue 410 The FORTH Language A Learner s Per spective st An Affordable Graphics Tablet for the Apple Interfacing Tips and Troubles Noise Problems Part One LSTTL Reference Chart Multi user Some Generic Components and Techniques Write Your Own Threaded Language Part Two Input Output Routines and Dic tionary Management e Make a Simple TTL Logic Tester Volume 2 Number 7 Issue 11 e Putting the CP M IOBYTE To Work Write Your Own Threaded Language Part Three Secondary Words Interfacing Tips and Troubles Noise Problems Part Two e Build a 68008 CPU Board For the S 100 Bus Writing and Evaluating Documentation e Electronic Dial Indicator A Reader Design Project Volume 2 Number 8 Issue 12 e Tricks of the Trade Installing New I O Drivers in a BIOS Write Your Own Th
24. TO SELECT CHANNELS TO BE READ LABELS FOR THEM AND r FILENAME TO USE FOR STORING DATA TO DISK DRIVE OUT 6 14 SET BAUD TO 9666 ERASE CLEAR SCREEN WSELECT 8 SELECT A WINDOW TO USE WINDOW 6 6 23 70 NFRANE _ 1 WINDOW 1 1 22 77 WCLEAR CLEAR SCREEN PRINT PRINT ENTER FILE NAME TO BE USED TO STORE DATA INPUT FNAMES PRINT PRINT ARE YOU SATISFIED WITH FILENAME Y ND I INPUT AS IF Ag lt gt Y THEN 268 NCLEAR CLEAR SCREEN PRINT FOR I si TO 7 GET CHANNEL DATA TKS I 8 INITIALIZE TICS TQ 6 PRINT SCHEDULE ANALOGS INPUT 3 16 Y N INPUT AS IF A N THEN 355 PRINT LABEL FOR INPUT amp Ip 8S INPUT LABELS I PRINT TIMING TICS s INPUT TKS I CHANNEL I si TURN ON CHANNEL FLAG PRINT IF TKS I THEN TKS I 31068 IF NOT USED CHECK SELDOM NEXT I TIKSI TKS 1 TIKSS TKS S PRINT PRINT PRINT ARE THE SELECTIONS AS YOU WANT THEN Y N S INPUT AS IF A lt gt Y THEN 319 OPEN 1 1 FNAMES OPEN FILE FOR OUTPUT PRINT COFFS PRINT SAMPLING WILL BEGIN WHEN YOU PRESS RETURW 5 INPUT AS A gt TIKS2 TKS 2 TIKSI 9 TKS 3 TIKSA TKS 4 TIKS6 TKS 6 TIKS7 TK8 7 Li 3 e AT THIS POINT UP TO 7 CHANNELS HAVE BEEN SELECTED FOR MONITORING AND SAMPLING WILL BEGIN WITH ANY INPUT FOR AS WEELECT 6 WCLEAR CURSOR 1 9 PRINT CURSOR 3 8 PRINT CURRENT DATE AND TIME PRESS CEBC TO END PR
25. Tf HighByte and 16 Then Value Value Analogin Values Ends Procedure Calcul ateSaap eteanSquar ed Begin SampleSue 6 8 For I 2 ta J Do SaepleSus SaapleGum BufferC 111 SampleMean SampleSua 7 J 1 SeapleMeanSquared Sqr Seap atwan Endi Procedure CalculataStandarddeviationi Begin Calcul ateSaspil eMeanSquar ed SusOfSquares 6 65 For I 2 to J Do Begin Element Buffer Iis Sua0fSquares i SueOfSquares Sqr Element s Ends StandardDeviation Sqrt SusOfSquares J 1 SaspleteanSquared 4 12 4 Endi Begin t Main Program Logic Port 61 143 t sets Kaypro baud rate to 9699 29 for a label to describe the input and the number of timing tics that must pass before that channel is read You ll need to experiment with these interrupt tics to determine how to schedule the tasks Ihaven t made any careful measurements but 200 tics seems to be about a second with the Kaypro and a 4 MHz CPU Other computers will vary greatly For each channel that is NOT selec ted the value of TKS is set to 31000 a big enough number so that the program won t spend time very often checking to see whether to execute that task Line 353 turns on the channel flag for each channel that s selected otherwise it stays 0 as it was initialized in 217 The OPEN statement at line 380 sets aside an output buffer for the selected sequential file The next statement unique to MT
26. and to activate the sample pump when the wind parameters are within ap propriate limits The environmental data as well as sample duration and time are stored in RAM Each system is battery powered and uses only 65 ma for monitoring and 350 ma when the pump is activated 9 The City of Grand Rapids uses an Atari home computer and an ADC to monitor the cyanide content in the wastewater they treat Cyanide isa pollutant that threatens the microorganisms used to treat waste and wastewater that contains cyanide must be shunted into a special holding area from which it can be released later ataratethat will cause no harm 10 To study the formation of pat terned ground in arctic permafrost regions an ADC in conjunction with a Radio Shack Model 100 was used by University of Washington Quaternary Research Center scientists to monitor strain gauges and temperature sensors buried in the soil Four systems have been deployed near Spitzbergen in Norway to record stresses and soil motion resulting from the annual The Computer Journal Issue 21 freeze thaw cycle The soil surface in this area is marked by a distinct pat tern of stone circles thought to result from the slow overturning of the soil in a convection cell manner The systems are battery powered and cold room tested to 40 C prior to field in stallation 11 A fruit storage company in Washington State uses an ADC anda Kaypro computer to monitor and con trol special
27. be virtually impossible to unstick things made with these glues imagine the fix our modern world would be in if the glue used to make plywood was not as strong as it actually is Solder is very much like the modern glue that blends into the surface of a material indeed it could be said that solder was the first example of this type of glue Fortunately though solder can be affected by the very thing that makes it work in the first place heat Obviously then the first step in unsoldering will involve reheating the joint It might seem to be the only thing required just heat up the joint and separate the two parts In some instan ces this will work but most of the time there are some real difficulties with this alone For instance since heat is in volved you can t use your fingers to reach in and pull things apart not without suffering severe burns to your fingertips a very painful burn indeed Some sort of forceps or pliers must be employed which can be awkward Because using tools is so tricky you may be tempted to heat the joint longer than necessary to be sure that the solder is liquefied that can lead to physical damage to adjacent parts especially the cicuit traces on the board As we won t be discussing ways to repair damaged traces until the next article in this series you ll want to avoid this problem for now Solder is interesting because it has properties similiar to the three dif ferent glues mentione
28. buying another one better to spend a little more to start with and save in the long term Now let s move to the king of the hill in solder suckers These are really in dustrial models that most part time electronics hackers would not have but it is useful to know they exist Basically these are little self powered vacuum cleaners attached to hollow tipped soldering irons They range in price from a couple hundred dollars up to a thousand or more They are very effec tive and often come with a bewildering array of accessories that make them at tractive to electronic assemblers faced with many solder joints to be un soldered Before we leave the topic there does exist a sort of missing link in the species It can be found in the Radio Shack menagerie Cat No 64 2061 This is a soldering iron with a right angled hollow tip that leads to a metal tube at the end of which is the old familiar solder sucker bulb The bulb is positioned such that it can be operated by the same hand that holds the iron The advantage of this tool is that the hollow tipped iron heats the joint and the bulb then sucks up the molten MTBASIC Multitasking Multitasking BASIC Compiler Compiler The Computer Journal Issue 21 solder without the hand swapping exercise inherent in the bulb or spring type It resembles the industrial model in its basic principle At first appearance this would seem to be the ideal tool but in my experien ce t
29. computer do anything Most readers can probably remember the feeling The shock of reality came a lit tle later while I was still in school and working for a security company My supervisor occasionally installed some fabulously expensive solid state security systems and it occurred to me that a computer like the Commodore 64 just then becoming really affordable could make all the decisions needed for commercial security I was right of course but nobody I talked with knew how to make the computer respond to inputs from security switches I was too busy with full time work and full time school to take on an additional study of electronics and begrudgingly let go of the idea Actually I gave up doing anything about it at the time but I couldn t quit thinking of fascinating projects that would be possible if my computer weren t limited to working just with its peripherals I had no shortage of ideas just no way to make any of them work I was the kind of person who passed over magazine articles and adver tisements dealing with analog digital electronics I d never had the oppor tunity to learn much of the terminology involved and dismissed the subject as something that would probably only in terest a technician anyway But when my business and computer training landed me a non technical job in a com pany that makes A D converters I managed to get myself hooked but good For the totally uninitiated as I cer
30. for the microcom puter environment Hundreds of NO LIMIT owners are creating highly interactive Software systems often utilizing existing mainframe code and saving time and money in the process Ver 2 0 features include EXTENSIVE GRAPHICS Get Put Paint Color Dot Line Box Circle Ellipse Large Characters FULL SCREEN CONTROL Windows Cursor Read Write Screen STRING MANIPULATION on Me Concatenate Extract Pack Justify ro Fi KEYBOARD CONTROL Read Key During Execution String Read With Edit FILE MANAGEMENT COMMUNICATIONS INTERRUPTS OTHER FEATURES Exist Rename Delete Full Interrupt Driven to 9600 Baud Set Com Line Send Receive Line Modem Status DOS Execution Program Execution Command Line Read DOS 3 0 Directories Peek Poke Random Numbers System Status etc And to complement NO LIMIT the VO PRO development system allows creation and editing of FORTRAN Pascal C callable screens This word processor type sys tem pays for itself several times over on your first project 260 For immediate solutions to your programming needs call 800 562 9700 512 251 5543 Texas M E F Environmental Inc PO Box 26537 Austin Texas 78755 Tademert of Microsoft inc Superscf inc Bid Corporation Fiyan Mcfartand and Microsoft inc reapectivedy Whether you program on the Macintosh the IBM PC an Apple li series a CP M i 3i system or the Commodore 64 your pro gram will run u
31. help When I recently reorganized all my literature I could find practically nothing on unsoldering among the dozens of features on soldering Had I stumbled upon some dark and mysterious art known only to a select few Some ancient ritual marked by ob scure incantations oaths and secret hand clasps Yes At least the part about odd hand clasps more about that later and as to the mumbled oaths almost any will do if they benefit the process But seriously the true purpose of this article is to delve into the in tricacies and problems of unsoldering as fully as space will allow In the initial article in this series on soldering it was stated that soldering is mostly science and partly art By science is meant hard knowledge about the process and what makes it work by art is meant the ex perienced judgement that comes from actual practice Unsoldering on the other hand hands that is more than two are very useful is more like 50 50 science and art Or to phrase it another way knowing what to do is equally as important as knowing when to do it and when not to We begin by reviewing the theory of soldering as it applies to unsoldering then we ramble into the jungle of un soldering tools including the techniques of using them Next we ll probe the art part applying the right tool and techniques Followed by the main skir mish unsoldering a DIP IC which leads us to all the things that can go wrong trying to unsolder a D
32. in between a computer and a terminal to trap data for later use could prove useful with mainframes that will not talk to other computers The units also can help with changes in baud and protocol operations by allowing you to store the data the unit has battery backup change formats and play the data back One use I can think of is in a busy office where the printer is located in a quiet area and the computers are all over the office You could get one of these for everybody and just have them take it to the prin ter for use no messy or long cables going to all systems Also let s not forget the protocol problems most LAN s will cost more per unit than this The Portapac can handle up to 256K of memory ours came with 32K and can be expanded to 64K by adding 6264LP 15 s It looks rather simple in side and well built so give Cryptronics a call if this fits any of your needs I may build one for myself along similar lines and if so will write it up in The Computer Journal B Continued from page 50 programs DO FOR loops with clean exits long variable names multi statement lines dynamic dimensioning a powerful assortment of string com mands and more Demonstration Disks are available with a full 30 day money back guaran tee Complete documentation is provided including a modern Keyword Dictionary and User s Guide The cost is 495 for micro operating systems CP M MS DOS and PC DOS 795 for most UNIX
33. is identified as a Byte so they can take on values from 0 to 255 quite appropriate for the purpose The BEGIN and the END show the compiler what code is actually part of PrintAt The procedure PrintAt calls another built in procedure called WRITE The first parameter for WRITE is Ist which tells Pascal that this output is to be sent to the LST device the printer When a WRITE procedure is used to send data to the CRT screen the most common case the first parameter is un necessary as the default is CON The printer is sent the values which represent ESC CTRL I for a horizontal tab and the character which represents the position wanted CHR X Then it s sent the values which represent ESC CTRL K for a vertical tab and the character which represents the vertical position wanted CHR Y Suppose now that your invoice form needs the variables Name and Address printed at column 20 on lines 5 and 6 and the variables City State and Zip printed starting at column 20 on line 7 with a comma between City and State and two spaces between State and Zip The code in the main logic to accom plish that would simply be PrintAt 20 5 Write lst Name PrintAt 20 6 Write lst Address PrintAt 20 7 VYritellst City State Zip Like the built in procedures Read Write and GotoXY you now havea GIVE YOUR COMPUTER THE ABILITY TO INTERACT WITH THE REAL WORLD ea MONITOR AND CONTROL TEMPERATU
34. order or to obtain literature si Echelon Inc 101FirstStreet Suite427 LosAltos CA 94022 415 948 3820 13 14 On the other hand perhapsit s the IC that you wish to recover and the circuit board that is useless obsolete or damaged for instance You ll have to make a judgement about this issue each time you unsoider anything Backing away from multi lead IC s it becomes obvious that the easiest thing to unsolder is a single connection part typically only wires fall into this category You can use the destructive technique of clipping the wire and then unsoldering the stub Let s spend just a moment on this method The advantage is that you can unsolder a stub by sim ply holding the circuit board in one hand apply the iron and when the joint turns molten rap the edge of the board against something solid such as your workbench and the stub will just fall out most of the time stubborn stubs are not unknown No need to bother with solder suckers etc You may need to use a little solder wick to clean up the pad on the board but rarely so This is the great appeal of the destruc tive method you lose the part but preserve the board and it s convenient Returning to the example of un soldering a single wire many times we won t wish to cut the wire because it will become too short also stranded wire leaves a stub of many little wires that are actually difficult to tap out of the hole In this case it is be
35. proofs are supplies so please type your ad or print legibly KEYBOARDS FOR COMPUTER BUILDERS Full ASCII numeric pad UC lc CAPS LOCK REPEAT SELF TEST Brand new hundreds sold to builders of Apples Xerox 820s Big Boards etc Parallel TTL output strobe 5 volts 100 ma Custom case available Keyboard 35 Documentation 21 pgs J cable pkg 5 Spare CPU ROM 4 UPS included Detailed specs on request Electrovalue Industrial Ine Box 376 CJ Morris Plains NJ 07950 201 267 1117 Voice Processor for the KAYPRO Com puter Unlimited speech contains all sof tware Call or write Busch Computer PO Box 412 West Haven CT 06516 Phone 203 484 0320 S 100 68008 CPU BOARD Detailed descrip tion in issue 16 of The Computer Journal A amp T 260 Kit 210 Bare Board 66 Prices include shipping INTELLICOMP INC 292 Lambourne Ave Worthington OH 43085 Phone 614 846 0216 after 6 p m Morrow Decision I S 100 system with MPZ 80 CPU DJ DMA floppy disk controller 256K static ram Wonderbus 170 on mother board Disk Jockey Hard Disk HDCA Con troller Sugart 800 floppy drive 10MB hard disk CP M Micronix Multiuser system un configured MP MII dBase II Wordstar Ac counting Plus Excellent condition 3500 some trades considered TCJ 190 Sullivan Crossroad Columbia Falls MT 59912 Phone 406 257 9119 S 100 Bus IEEE 488 Interface Card with cable manuals and software for North Star Horizon Purchased n
36. reverse of this routine is useful to save 8 procedure to disk If you ve just writ ten a terrific procedure that will sim plify all your future programming take the time to mark the top of the block The Computer Journal Issue 21 with a CTRL K Band the bottom witha CTRL K K then type CTRL K W and give the editor a file name when it asks Just like you know what Functions All the manipulation techniques described so far apply equally to procedures and functions but the two are somewhat different in use A procedure is like a tiny program that accomplishes a single useful task whereas a function is like a variable that takes on a particular value accor ding to specified operations Since all the built in procedures and functions of Turbo Pascal are included as part of the runtime library that becomes a part of each compiled program routines that are not often used are not built in for reasons of space These built in features take up nearly 10 K of memory meaning that the very smailest of programs when compiled will be at least 10 K long It s amazing what can be accomplished with that 10 K of library but that s not the point Everyone will sooner or later miss a favorite keyword from another language It s inevitable so let s ex pand on an example mentioned briefly before BASIC offers easy exponen tiation using the operator To find the cube of the variable A for example one can express it as A 3 Suc
37. so variables like TICS1 vvabash Pinnacle Serves C DISKETTES ET Certified 100 Error Free ed MEE Meets all Industry Standards Li Manufacturer of Magnetic Media lor Over 20 years BOXED with ENVELOPES and LABELS Reinforced Hub Ring Lifetime Warranty 1 0 1 00 5 25 SSDD SOFT SECTOR w hub ring 95 77 5 25 DSDD SOFT SECTOR w hub ring 1 09 88 ZEB DATATECH UNIQUE EASEL BACK CASE functions as Library Box for convenient permanent storage and easy diskette access 1 0 100 5 25 SSSD SOFT SECTOR w hub ring 98 91 5 25 SSDD SOFT SECTOR w hub ring 1 18 5 25 DSDD SOFT SECTOR w hub ring 1 28 5 25 DSQD SOFT SECTOR w hub ring 5 25 SSSD 10 SECTOR HARD w hub ring 8 SSSD SOFT SECTOR Unformatted 8 SSDD SOFT SECTOR Unformatted 8 DSDD SOFT SECTOR Unformatted 3 5 SSDD 135 TPI 2 59 3 5 DSDD 135 TPI 3 69 SUPER SPECIAL 5 25 HIGH DENSITY DISKETTES for use on IBM PC AT 10 2 35 each 100 2 20 each DEALERS SCHOOLS USER GROUPS CALL FOR VOLUME DISCOUNTS Terms Add 3 shipping amp handling for U S orders Outside USA add 10 to cover postage In Illinois add 7 sales tax or provide resale certificate Prices amp terms subject to change without notice CALL TOLL FREE orders only MA 1 800 222 1248 Ss in Illinois or for information 312 882 8315 AUTHORIZED WABASH DISTRIBUTOR DIGITAL IMAGES 1185 TOWER RD SCHAUMBURG IL 60195 Lifetime Warranty
38. stand how it all works Suppose we want to get data to a terminal in assembly this is usually called CONOUT The routine would first check to see if the device is ready then get the data and output it to the device Next it would flag to indicate completion then return to the main program The way Forth works is to break each individual operation into words think of MACROS Our assem bly program would then be CONOUT TEST GETDAT OUTDAT FLAG RETURN When assembling the macro program the assembler would actually write the code and assemble it as if you coded it by hand Forth however would assemble the addresses of the machine code portions that perform the functions and then CALL them in sequence The difference in code sizes is due to the fact that Forth only assem bles the machine code once and then references that location there after The macro assembler however would insert machine code whenever the routine was used Suppose that CONOUT used 25 machine code in structions and our program called it 10 times If one call instruction is con sidered as one instruction then the Forth program would be 25 10 fora total of 35 machine instructions com pared to the macro s 250 instructions 10 times 25 The macro version might actually be faster without all the jum ping but the Forth version would be much smaller Optimizing the Macro code would have you calling the routine where the code was placed instead of repeating
39. that none of its range was wasted With 8 bits of resolution each increment you could measure would be nearly 8 wide With 12 bit resolution the increments would each be less than 0 5 and with 16 bit resolution 1 in 65 535 you could be ac curate to within 0 039 I promised you that resolution has something to do with both cost and speed didn t I Well as you might ex pect 12 bit systems are generally more expensive than 8 bit systemsand __ usually slower How slow Even inex pensive 8 bit systems can often read thousands of samples per second If your application requires that kind of speed AND your computer and language can do something with infor The Computer Journal Issue 21 mation coming in that fast AND you can get by with 1 in 256 resolution then consider one of the fine 8 bit systems that are available Other factors being equal it will cost the least If you need more resolution 12 bits will provide 1 in 4096 as mentioned earlier Most 12 bit ADCs on the market will sample at speeds from 5 or so up to 100 samples per second As with all the other factors your ap plication is important here To digitize speech patterns might require many thousands of samples per second whereas someone monitoring the movement of a glacier might be well served by one measurement a week Some ADC systems are made up of a basic circuit board to which optional modules can be connected thus providing a choice of the
40. the Handler as a high level language with built in routines for the non critical code sec tions A possible candidate is C and I have the BD Software C compiler to evaluate for this use BDS C has the ad vantages of a small run time overhead the ability to include only the library files which can be either C or 8080 assembler HEX code actually used and it can produce ROMable code The awkward part is that you have to use a word processor to generate or change the source code then compile and link the program before you can run it Then if you want to change a portion written in assembler you have to rewrite the Source using a word processor assem ble to a HEX file put the new file in the library and then compile and link the C program I m putting heavy emphasis on the ease of revising the program and many people won t agree with this because they don t need it but when working on a robotics application you ll APPLE Jf I e amp c OWNERS The Computer Journal Issue 21 want to make frequent changes in the sequence of motions the speed the position the dwell time etc In these cases an interactive BASIC like language would be convenient if it was fast enough for real time control Another possibility for the Handler is MTBASIC which includes a flash compiler has the ability to call machine language subroutines with argument passing and can include in line machine language code You can even write
41. the code every time it was used The size of the optimized Macro code would be the same as the Forth code but faster than Forth s threading I have been considering creating a language based on Forth s threaded features but using the microprocessor type architecture We could take the Z80 assembly code and call this the language with the kernal being actual Z80 machine instructions For use in other machines simulation of the Z80 instructions in the kernal is all that is needed Think about it what it means is being able to disassemble a program or use a PROGRAM ASM file load the program into 280 Forth and have it run directly on a 68000 machinel In reality I am borrowing Moore s concept of a universal design except that mine would be register oriented instead of stack oriented All other features would be the same Enough speculation I ll have more on the ROMing of Forth later and will see how many people can find errors with my idea of a new language Televideo TPC I A recent release of the discontinued Televideo protable Z80 computers called TPC I at 795 has caught my at tention I purchased one for my mother in law to use at college and decided to check it out The case is all plastic so getting into it was a big chore It all snaps together even though there are screws mainly for looks board that covers the whole end of the unit has the computer It has two Teac FD55B drives a nice 9 inch monitor and 6
42. then there is no reason to protect it and you should in stead try to protect the circuit board AFFORDABLE ENGINEERING TRSDOS PCDOS SOFTWARE gt sers vou FREE Free to create computer environments right for you free to automate repetitive tasks free to increase your productivity Z System the high performance 8 bit operating system that flies Optimized assembly language code full software development system with linkable libraries of often needed subroutines relocating ROM and RAM macro assembler linker librarian cross reference table generator debuggers translators disassembler ready to free you New generation communications package provides levels of flexibility func TERM lil tionality performance not available until now Replaces BYE and XMODEM master server local area network capability public or private bulletin board and electronic message handling are integral features auto dial answer menu install XMODEM CRC Checksum MODEM7 Batch Kermit CIS and XON XOFF protocols 100 page mantual i Hie a ei Tel ep eres OG dar E 99 00 Rolis Royce of message handling systems mates with TERM ill or BYE for Z MSG most advanced overall electronic mail file transfer capabilities menu installed extreme configurability many levels of access and security word phrase editor field search complete message manipulation and database maintenan
43. ticles will not stick to it but can wedge themselves into the tube use a thin probe e g a toothpick to poke them loose Proceeding up the evolutionary lad der of solder suckers we encounter the next great advance the spring loaded sucker In the Radio Shack catalog these are more politely termed Desoldering tools Catalog Nos 64 2098 and 64 2085 Early on it was found that the bulb type is tiring if you unsolder many joints and also requires a well developed technique to work consisten tly The spring loaded tool overcomes these problems The tool consists of a tube similiar in shape to a syringe in side there is a piston that is forced to the top of the tube by a spring There is a fingerhold by which you compress the piston down against the spring until it catches on a trigger in some designs the piston has a shaft extending from the top and this shaft is pushed down to prime the tool To use the spring tool first prime it by forcing the spring down the designs vary so you ll need to figure out how to do this most of the tools have fingerholds that allow this step to be done with one hand allowing the other hand to hold and manuever the soldering iron Congratulations you now know the strange hand grasps Next you proceed as with the bulb type heat the joint and when the solder is molten remove the iron place the desoldering tool over the joint and release the trigger The spring will snap up creating a sh
44. together have achieved modern sockets that perform equivalently to a soldered connection Yet the early problems still influence some builders who may not use sockets at all Others use only a certain brand or especially avoid some brands Buying from a reputable source should result in a good quality socket always chose the gold plated type as the small extra cost is worth it Now we circle back to a very subtle reason for omitting sockets directly related to unsoldering Commercial assemblers have available repair Continued on page 3 INTELLICOMP Introduces Inexpensive S 100 68008 The card pictured above is 65 for the bare board 210 for the kit or 265 assembled and tested It uses only standard parts A sample BIOS for CP M 68K is available on disk for 20 The board works fine with Digital Research Computers 64K RAM boards and semi disks A detailed description of the board appears in Issue 16 of The Computer Journal For additional information call Intellicomp Inc at 614 846 0216 evenings best time or write to Bruce Posey Intellicomp Inc 292 Lambourne Ave Worthington OH 43085 The Computer Journal Issue 21 19 Analog Data Acquisition and Control Connecting Your Computer to the Real World by Jerry Houston Analog Fundamentals After my first data processing class in college Business BASIC of course I felt ready to take over the world Nothing could stop me now I could make a
45. use Plug in cartridges will be used for program distribution data back up and data interchange but the computer will have enough non volatile memory to hold all the programs and data used by the average person so that they load the computer once and then just turn it on and use it without having to reload One of the current buzz words is user friendly but programs are NOT easily used by the general public anda The Computer Journal Issue 21 TURBO AUTHORS WANTED for the Turbo Pascal Handbook Know a good set of Turbo routines Perhaps you have developed your own libraries What do you know about using Turbo to manage assembly language libraries Operating system calls I O Write about it The Turbo pascal handbook needs your article now Write to The Computer Journal for more information and an author s guide The Computer Journal 190 Sullivan Crossroad Columbia Falls MT 59912 Phone 406 257 9119 lot of work still remains to be done in this area One of the problems is that people have been over sold on what a computer can do Small business owners who can not even balance their checkbook have been led to believe that ifthey buy a computer and an accoun ting program they can take care of their books Accounting programs area tool which enable someone capable of doing accounting to do it more easily and more accurately but they don t enable someone with no training to set up and maintain their bo
46. very simplest ADCs offer as few as 4 or 8 analog intputs and little else In fact they re not really ADCs because the C is missing the control function They re useful for monitoring analog sensors and laboratory ap paratus where the purpose is to log data to a printer or disk file The next step usually includes some number of digital outputs as well as analog inputs With such an interface a computer can monitor the temperature for example and turn on a furnace or air conditioner when it s needed If the ADC also includes digital in puts the computer can monitor ON OFF conditions such as security switches or event counters Since digital inputs can be monitored directly by a computer an ADC isn t really needed for this particular job but digital inputs on an analog interface are pretty handy anyway If the computer controls a home environment it needs to monitor analog parameters light temperature moisture sound and so on and if digital inputs are available the computer can handle the security needs as well The ADC will pass properly conditioned digital values to the computer in a manner that makes programming easy Two other features are sometimes useful the BSR transmitter already The Computer Journal Issue 21 mentioned and D A outputs D A con version is the reverse of A D naturally and means that the ADC will output an analog voltage that represents a digital value passed to it by the compu
47. window is properly framed it is re defined to be one character smaller in each direction so the framing charac ters are protected from overwriting The next lines just print prompts to the screen and ask the user whether to schedule each of the first seven analog input channels If the answer for a channel is yes then the user is asked BMON Software In Circuit Emulator Links your CP M computer with any Z80 based computer or controller that you may develop All that is needed is BMON 8K of ROM space and a handshakeable bi directable 1 O port either RS232 or Paral lel Features Full program development debugger with Breakpoints Snaps Stops amp Waits Single Step program execution Download file from CP M system to de velopment RAM Upload Memory irom development RAM to CP M disk Two versions Master BMON runs in your CP M system Slave BMON runs in your target system Note Requires Microsofts M80 amp L80 assembler amp linker to setup Slave BMON 8 SSSD Disk containing Master BMON Slave BMON CONSOL BMONIO CONSOLIO and Users Shipped Via prepaid UPS No COD or PO Box Check or Money Order to Barnes Research amp Development 750 W Ventura St Altadena CA 91101 818 794 1244 CP Mis a trademark of Digita Research inc M80 amp 180 are trademarks of Microsoft inc 1918 1928 1930 1948 1956 1968 1978 1966 1996 2600 2810 2029 2836
48. workstations and 1995 for multi user minis such as VAX For fur ther information call 801 224 6550 or write to TransEra Corp 3707 North Canyon Road Provo UT 84604 u 52 The Computer Journal Issue 21 THE COMPUTER CORNER I made it back alive from the SOG Semi Official Get together sponsored by Micro Cornucopia in Bend Oregon This beautiful recreation area of cen tral Oregon was the site for a get together that brought in several people from outside the U S At the barbeque on Thursday night a showing of hands made it clear that the largest part of the attendees were from east of the Rocky Mountains rather impressive for a free event Things got started Friday with seminars and product displays About 300 people were there Friday with more people expected on Saturday and Sunday those poor working types While we were only able to attend the Friday stuff there is no question that all three days were a success Some of the speakers had a lot of information to give even though the titles of seminars were a bit cryptic Only a few of the seminars had conflicting times so you could stop in anyway to see if one fit your needs Jack Denton the author of RPM which I reviewed some time ago started the session with an overview of CP M which really turned out to be a discussion of the known bugs in CP M and how to correct them For us system type programmers this was great Later on there were talks on O
49. your BDS C Compiler today Complete Package two 8 SSDD disks 181 page manual 150 Free shipping on prepaid orders inside USA VISA MC COD s rush orders accepted Call for information on other disk formats lnc BDS C is designed for use with CP M 80 Operating systems version 2 2 or higher it is not currently available for CP M 86 or MS DOS BD Software Inc P O Box 2368 Cambridge MA 02238 617 576 3828 Unsoldering The Arcane Art Second in a Series on Soldering Unsoldering and PC Board Repair by James O Connor The Computer Journal Issue 21 W hy do you think they put erasers on the end of pencils Who hasn t heard that old chestnut and the answer is because people make misteaks mistakes eras errors whatever The spelling checker program will blow a binary fuse when it tries to digest that sentence Just as things go wrong when using a pencil they also go awry when soldering From the moment you begin to soider things together inevitably you ll solder the wrong thing in the right place or the right thing in the wrong place And if you get really in volved in electronics you ll want to un solder components because they are under suspicion of malfunctioning Having determined that you must unsolder something you might naturally consult your reference material for some helpful hints and if your referenece library is similiar to mine you may find a glaring lack of any
50. 10094 Error Free DISKETTES The Computer Journal Issue 21 couldn t be used It IS ok to use keywords entirely within a variable name so something like XTICS1 would have been alright That s about it for the main logic Line 540 uses the KEY function to check for an ESCAPE key pressed ASCII value 27 and gracefully exits the program in that case remember to turn ON the cursor if you ve turned it OFF All that s necessary once the tasks have been listed in RUN statements is to keep Task 0 executing until you re ready to quit I did it here by checking for a key pressed but the same thing can be accomplished by using a line that does a GOTO to itself I think it makes more sense to provide an exit from the program so I just keep checking for an input that signifies it s time to stop As mentioned before the first seven tasks here are very similar They start with a TASK statement like the one in line 640 and end with an EXIT statement like the one at 870 Because these seven tasks all acquire data from the same peripheral they must disable interrupts while reading that data Otherwise it would be possible for several tasks to be sending conflicting commands to the ADC 1 This is accomplished with the INTOFF interrupts off in 655 and the INTON interrupts on in 865 The rest of the analog read logic is identical to that used in Program One except that these tasks also contain some code to print results to the CRT scre
51. 14 The maker of a popular brand of disposable diapers uses an Epson HX 20 and an ADC equipped witha moisture sensor to test new types of lining materials This research should lead to more efficient linings for the diapers and dryer babies Vendor Listing A listing of suppliers that manufac ture ADC equipment is provided for the convenience of those who want to The Computer Journal Issue 21 find out more about particular equip ment The usual authors disclaimers must apply along with my apology to any company that I haven t found out about yet The products that I have listed range from inexpensive to not so and from simple to complex I ve included ADCs that are useable with a variety of com puters and left out some that are an ac cessory for one system only It is therefor not a complete listing but a very good place to start Because many of the products are better known by name than the companies that make them they re listed alphabetically by product name in the vendor list Program Narratives Two programs accompany this ar ticle Program One is written in Turbo Pascal and measures the performan ce of ADC systems in terms of how fast analog channels can be read Program Two is written in MTBASIC and lets the computer operate as a multi channel data logger In each case code is used that reads the analog inputs of the ADC 1 Data Acquisition and Control System from Remote Measurement Systems
52. 4K of memory expandable to 128K The disk controller is a 1770 5 inch only and there is an R6545 video controller for the GEM package There is a 280 with several special chips handling unknown functions no schematic provided My unit is clean with only one jumper on the board rev Bl and it physically looks good except for the case Other than adding more memory I would guess the unit could not be changed or modified no adding 8 inch drives If you are not concerned about the hardware the units seem to work pret ty well and come with a full com plement of software I am not necessarily recommending that you buy one of these but only letting you know that they work appear to be made OK but will not let you expand on them which is what I always need to do Portapac What I can recommend for those who carry data from one place to another is the Portapac by Cryptronics 11711 Coley River Circle Suite 7 Fountain Valley CA 92708 phone 714 540 1174 This rather small 500 unit can inter cept serial data and store itin memory for playing back later or elsewhere We bought this unit to help with an in 51 dustrial problem mainly slow and troublesome tape cassettes We needed some way of taking data from one location where the controller was and bring it to our shop where a regular computer could debug it and make changes Now that we have the unit in our hands all sorts of uses come to mind It can fit
53. 721 Starr King Circle Palo Alto CA 94306 tel 415 493 3735 Write Hand Man trademark of Poor Person Software CP M trademark of Digital Research Sidekick trademark of Borland International dBase trademark of Ashton Tate WordStar trademark of Micropro SuperCak a trademark of Sorcim APROTEK 1000 EPROM PROGRAMMER only 250 00 A SIMPLE INEXPENSIVE SOLUTION TO PROGRAMMING EPROMS The APROTEK 1000 can program 5 volt 25XX seres through 2564 27XX senes through 27256 and 68XX devices plus any CMOS versions of the above types Included with each programmer is a personality module of your choice tothers are only 10 00 ea when purchased with APROTEK 1000 Later vou may re quire future modules at only 15 00 ea postage paid Available personality modules PM2716 PM2732 PM2732A PM2764 PM2764A PM27128 PM27256 PM2532 PM2564 PM68764 includes 68766 Please specify modules by these numbers APROTEK 1000 comes complete with a menu driven BASIC driver programmer listing which allows READ WRITE COPY and VERIFY with Checksum Easily adapted for use with IBM Apple Kaypro and other microcomputers with a RS 232 port Also included is a menu driven CPM assembly language driver listing with 2 80 DART and 8080 8251 VO port examples Interface is a simple 3 wire RS 232C with a female DB 25 connector A handshake character is sent by the programmer after programming each byte The interface is switch selectable at the following 6 ba
54. 80 assembly language code fuli software development system with proven linkable libraries of productive subroutines relocating ROM and RAM macro assembler linker librarian cross reference table generator debuggers translators and disassembiers ready to free High performance and flexibility Productivity results from dynamically customized OS environ Real time control kernet option allows quick software development for industrial control applications other tools and utilities for office desk top personal compuung functions local area networks to Ethernet AppleTalk Omninet ArcNet PC Net Sytek from micro to mainframe command control and communications Distributed processing application programs are easily Extreme organizational flexibility each directory another environment e Aliases complex series of commands known by simple names with variable passing Named Directores with absolute password security Full screen command line editing with previous command recall and execution Shells and Menu Generators with shell variables Command file search Paths dynamically alterable Screen oriented file manipulation and automatic archiving and backup 512 megabyte file sizes 8 gigabyte disks handled TCAP database handies characteristics of over 50 computers and terminals Tree structured online help and documentation subsystem Your missing link has been found ZI Now fly with eagles Fast res
55. ADC and sensors to measure wind speed and direction temperature and relative humidity Every fifteen minutes throughout the day the C 64 calls the remote stations in sequence and acquires up to the minute meteorological data The Atlanta area is characterized by small agricultural areas that differ dramatically in weather Because of this system far mers in each of these regions now have access to vital regional weather infor mation not available until now 2 A southern California electronics firm is using an ADC controlled by an Apple IIe computer to perform final manufacturing tests and calibration of medical power supplies All 16 of the ADC s analog inputs are employed to measure voltages at test points under various load conditions The power supply loads are applied systematically via the ADC s power line carrier remote control system The computer is programmed to prompt the technician when an adjustment is required or a unit is defective and to produce a printout of the final test results Even the clock frequency is monitored via a frequency to voltage converter It is estimated that the automated power supply checkout is now accomplished in one seventh the time that a technician previously required 3 Amana has reduced the time required to test room air conditioners from 20 minutes to only 2 minutes through the use of an ADC monitored by a Commodore 64 computer The new test which monitors the rate of tem
56. Appleworks screen Eight BSR serial ports for future expansion Full documentation included in a users manual Includes more software on disk firmware in 4K EPROM 399 The cost is 60 for the universal base and 8 50 for each cartridge driver kit from Computer Friends 6415 SW Canyon Ct Suite 10 Portland OR 97225 phone 503 297 2321 or 800 547 3303 Editor s Note We have been using a Macinker for over a year to ink six to eight Epson MX 80 ribbons a month and are would not want to do without it Basic 52 Computer Controller The Micromint BASIC 52 Com puter Controller is a standalone single board microcomputer which needs only a power supply and terminal to become a complete system programmable in BASIC or machine language The BASIC 52 uses the Intel 8052AH BASIC microprocessor which contains a ROM resident 8K byte floating point BASIC interpreter It contains sockets for up to 48K bytes of RAM EPROM an intelligent 2764 128 EPROM programmer 3 parallel ports a serial terminal port with auto baud rate selection a serial printer port and is RAM 80e An advanced digital VO interface card for the Apple Provides four 8 bit ports and two additional lines for handshake per port Has interrupt 43 bus compatible with the Micromint BCC11 BCC21 Z8 SystemsiControllers and BCC series expansion boards The BASIC 52 treats the EPROM as write once mass storage When a BASIC application p
57. B communicates with the outside world via its on board interface sockets The placement pin assignment and explanation of the interface sockets are shown in Figure 12 Using R W Memory In The Program Memory Space Since the 8035 can only execute instructions from its program Figure 10 Photo of the completed CD 1 memory which is read only memory there is no capability for writing dynamic program instructions into the program memory area Furthermore since the size of the program memory is only 4K bytes the manufacturer decided not to give the CPU direct memory access DMA capabilities What this means is that the program memory of the 8035 was meant to be PROM or EPROM With the CD 1 memory board it is possible to write dynamic programs in to the 8035 program memory space This is done by having the CD 1 memory board perform a DMA The DMA is accomplished by the following sequence of events 1 Refer to Figure 15 concerning this explanation Placing the run examine switch on the memory board to the examine position closed pulls the reset input on the CPU LO through diode D1 This puts the CPU in the reset mode 2 The data bus is disconnected Tristated from the CPU when the CPU is in the reset mode Also with the run examine switch in the examine position a ground is ap plied to the base of inverting tran sistor T1 The output of the inver ting transistor is applied through the memory board interface
58. Disk Formats e Sending Morse Code With an Appleji e Beginner s Column Part Two Basic Concepts and Formulas in Electronics Volume 1 Number 3 Issue 43 e Add an 8087 Math Chip to Your Dual Processor Board Build an AID Converter for the Applejf e ASCII Reference Chart Modems for Micros e The CP M Operating System Build a Hardware Print Spooler Part Two Construction Volume 1 Number 4 issue 4 e Optoelectronics Part One Detecting Generating and Using Light in Electronics e Multi user An Introduction Making the CPIM User Function More Useful Build a Hardware Print Spooler Part Three Enhancements Beginner s Colimn Part Three Power Supply Design Volume 2 Number 1 Issue 5 Optoelectronics Part Two Practical Applications Multi user Multi Processor Systems o True RMS Measurements Gemini 10X Modifications to Allow both Serial and Parallel Operation Volume 2 Number 2 Issue 6 Build a High Resolution S 100 Graphics Board Part One Video Displays f e System integration Part One Selecting System Components Optoelectronics Part Three Fiber Op tics Controlling DC Motors e Multi User Local Area Networks DC Motor Applications Volume 2 Number 3 Issue 7 Heuristic Search in HI Q Build a High Resolution S 100 Graphics Board Part Two Theory of Operation Multi user Etherseries e System Integration Part Two Disk Con trollers and CP M 2 2
59. E CONVERT INP S6 OUT 32 2 SECOND CONVERT INP 34 CURSOR 1 48 99 eww wo 9 ow o9 ov ow ovo ss The Computer Journal Issue 21 DATA TO DISK TASK FLAG INTERRUPTS BACK ON END OF TASK 5 DEFINE BEGINNING OF TASK 6 SKIP IF CHANNEL NOT SELECTED INTERRUPTS OFF SELECT ORIGINAL WINDOW SET CURSOR TO PRINT MSG PRINT READING MESSAGE START A D ON CHANNEL 6 WAIT FOR REPLY FROM ADC 1 GET UNUSED REPLY ASK FOR HIGH BYTE OF DATA WAIT FOR REPLY GET HIGH BYTE OF DATA NOT FINISHED A D YET ASK FOR LOW BYTE OF DATA WAIT UNTIL RECEIVED GET LOW BYTE OF DATA MASK FOR 4 DATA BITS USED COMBINE INTO TOTAL VALUE CHECK NEGATIVE FLAG SET CURSOR TO ERASE MSG ERASE READING MESSAGE SET CURSOR TO PRINT VALUE PRINT VALUE READ DATA TO DISK TASK FLAG INTERRUPTS BACK ON END OF TASK 6 DEFINE BEGINNING OF TASK 7 SKIP IF CHANNEL NOT SELECTED INTERRUPTS OFF SELECT ORIGINAL WINDOW SET CURSOR TO PRINT MSG PRINT READING MESSAGE START A D ON CHANNEL 7 WAIT FOR REPLY FROM ADC t GET UNUSED REPLY ASK FOR HIGH BYTE OF DATA WAIT FOR REPLY GET HIGH BYTE OF DATA NOT FINISHED A D YET ASK FOR LOW BYTE OF DATA WAIT UNTIL RECEIVED GET LOW BYTE OF DATA MASK FOR 4 DATA BITS USED COMBINE INTO TOTAL VALUE CHECK NEGATIVE FLAG SET CURSOR TO ERASE MSG ERASE READING MESSAGE SET CURSOR TO PRINT VALUE PRINT VALUE READ DATA TO DISK TASK FLAG INTERRUPTS BACK ON END OF TASK 7 DEFINE BEGINNING OF TASK 8 INTERRUPTS OFF DURING
60. IP We finish by discussing construction methods and how they affect the whole problem of unsoldering Theory In the first article we began by talking about welding separating things that have been welded together is very straightforward since welding makes one object out of two the only way to reverse the process is to simply cut the one object into two pieces We talked about welding to emphasize that soldering is different we proposed the analogy that soldering is more like gluing things together that solder can be thought of as a heat activated metallic glue Glues stick things together so if the glue can be unstuck the parts can be separated Glues come in several different types and the properties of each type affects how to unstick them Some glues dry very brittle and can be separated by fracturing them the old hide glue used on early furniture behaved this way it would fracture with age which is why old furniture often has wobbly joints Some glues never really harden they just stay sticky these can be defeated either by using a solvent to disolve them or in some cases by heating the glue until it releases the glue used on floor tiles is like this heat it up and you can pry up the tile Modern white glue that is used for wood and paper is made from chemicals that are very similar to the actual binders in natural wood and these blend right into the surface struc ture If they are waterproof then it may
61. ISSN 4 0745 9331 THE COMPUTER JOURNAL For Those Who Interface Build and Apply Micros Issue Number 21 November December 1985 2 50 US Extending Turbo Pascal Customize With Procedures and Functions pase 2 Unsoldering The Arcane Art Second ina Series page 8 Analog Data Acquisition and Control Connecting Your Computer to the Real World pase 19 Build the Circuit Designer 1 MPB Part 2 Programming the SBC pase3s The Computer Corner m a The Computer Journal Issue 21 THE COMPUTER JOURNAL 190 Sullivan Crossroad Columbia Falls Montana 59912 406 257 9119 EditoriPublisher Art Carlson Production Assistant Judie Overbeek Circulation Donna Carlson Technical Editor Lance Rose Contributing Editor Ernie Brooner Contributing Editor Neil Bungard Contributing Editor Bill Kibler The Computer Journal is a bimon thly magazine for those who interface build and apply microcomputers The subscription rate is 14 for one year 6 issues or 24 for two years 12 issues in the U S Foreign rates on request Entire contents copyright 1985 by The Computer Journal Advertising rates available upon request l To indicate a change of address please send your old label and new ad dress Postmaster Send address changes to The Computer Journal 190 Sullivan Crossroad Columbis Falls Montana 59912 Address all editorial advertising and subsc
62. Isolated pads simply can t dissipate heat very well without a trace heat is confined in the pad and quickly delaminates it On double sided boards the plated thru holes help an chor the pads in and sometimes there isa trace but on the top side under the IC where it can t be seen Of course the pad isn t actually necessary it s there because the pat tern used to make the printed circuit included pads for all the leads You only need to repair an isolated pad for ap pearance sake or if you need to attach a jumper to the lead a pad facilitates that And in the next article we discuss glue on pads that make such a repair rather easy to accomplish To Socket Or Not To Socket That Is The Question With apologies to the Bard of Avon this brings us to the matter of using sockets or eschewing them You may ask why discuss this in an article about unsoldering things the reason is very e ee 6 t aee 44425AA se V ERMENI i DPLILERIIII LIIIPILPPPI yE SH setveseqe LETTES 1429 l abeeedsaee p toise M o em t simple if you control how something is put together then you also affect how difficult it may be to take it apart Looking at commercially produced circuit boards you ll notice the distinct lack of sockets There is one very ob vious reason for this sockets cost money and for companies producing large numbers of boards omitting them adds up to big savings For the casual builder th
63. M and source code to copy yourself Games business utilities All FREE CP M USERS GROUP LIBRARY Volumes 1 92 46 disks rental 45 SIQIM USERS GROUP LIBRARY Volumes 1 90 48 disks rental 45 Voiumes 91 176 44 disks rental 50 SPECIAL Rent all SIG M volumes for 90 K U G Charlottesville 25 Volumes 25 IBM PC SIQ PC DOS LIBRARY Volumes 1 200 5 disks 200 174 FORMATS AVAILABLE SPECIFY Public Domain User Group Catalog Disk 5 pp CP M only payment In advance please Rental is for 7 days after receipt 3 days grace to return Use credit card no disk deposit Shipping handling amp insurance 7 50 per library 619 914 0925 Information 9 5 619 727 1015 anytime order machine Have your credit card ready VISA MasterCard Am Exp Public Domain Software Center 1533 Avohill Dr Vista CA 92083 40 Table 4 B0C35180C48 Instruction Set Courtesy of Intel ADD A A Add register to A ADD A R Add data memory to A ADO A data Add immediate to A ADOC A R Add register with carry ADOC A OR Add data memory with carry ADOC A data Add immediate with carry ANL A R And register to A ANL A OR And data memory to A ANL A data And immediate to A ORL A R Or register to A ORL A QR Or data memory to A ORLA data Or immediate to A XRL A A Exclusive or register toA XRL A GR Exciusive or data memory to A XRL A data Exclusive or immediate to A
64. N CHANNEL 3 WAIT FOR REPLY FROM ADC t GET UNUSED REPLY ASK FOR HIGH BYTE GF DATA WAIT FOR REPLY GET HIGH BYTE OF DATA NOT FINISHED A D YET ASK FOR LOW BYTE OF DATA WAIT UNTIL RECEIVED GET LOW BYTE OF DATA MASK FOR 4 DATA BITS USED COMBINE INTO TOTAL VALUE IF BANDIHBYTE 14 THEM RESULT RESULT CHECK NEGATIVE FLAG CURSOR 13 3 PRINT FPRINT IS 2 RESULT K 1 SENSOR 3 TASK 4 IF CHANNEL 4 THEN 1659 INTOFF WSELECT CURSOR 15 3 PRINT DX READING gt gt 5 OUT 4 3 IF BAND CINP 6 1 8 THEN 1468 CHARIN INP 4 OUT 4 161 IF BAND INP 6 1 THEN 1519 HBYTE INP 4 IF 86ND HBYTE 128 THEN 15300 OUT 4 145 IF BANDIINPIO 1 9 THEN 1559 LBYTE INP 4 HMASK BAND HBYTE 15 RESULT LBYTE 256 HMASK SET CURSOR TO ERASE M58 ERASE READING MESSAGE SET CURSOR TO PRINT VALUE PRINT VALUE READ DATA TO DISK FLAG INTERRUPTS BACK ON END OF TASK 3 eee vee DEFINE BEGINNING OF TASK 4 SKIP IF CHANNEL NOT SELECTED INTERRUPTS OFF SELECT ORIGINAL WINDON SET CURSOR TO PRINT M88 PRINT READING MESSAGE START A D ON CHANNEL 4 WAIT FOR REPLY FROM ADC 1 GET UNUSED REPLY ASK FOR HIGH BYTE OF DATA WAIT FOR REPLY SET HIGH BYTE OF DATA NOT FINISHED A D YET ASK FOR LOW BYTE OF DATA WATT UNTIL RECEIVED GET LOW BYTE OF DATA MASK FOR 4 DATA BITS USED COMBINE INTO TOTAL VALUE SS ewe eee o 9 9 ow vos t on IF BA
65. ND HBYTE 16 THEM RESULT RESULT CHECK NEGATIVE FLAG CURSOR 15 3 PRINT CURSOR 15 66 FPRINT IS Z RESULT Ke 1 SENSOR 4 INTON EXIT TASK 5 IF CHANNEL 5 THEN 1936 INTOFF WSELECT 8 CURSOR 17 3 PRINT gt gt READING gt gt OUT 4 4 IF BANDIINP 6 1 THEN 1756 CHARIN INP 4 OUT 4 161 IF BANDCINP 4 1 THEN 1789 HBYTE INP 4 IF BAND HBYTE 128 THEN 1779 OUT 4 145 IF BAND INP 6 1 9 THEN 1829 LBYTE INP 4 HMASK BANDIHBYTE 15 RESULT LBYTE 256 HMASK SET CURSOR TO ERASE MS8 ERASE READING MESSASE SET CURSOR TO PRINT VALUE PRINT VALUE READ DATA TO DISK TASK FLAG INTERRUPTS BACK ON END OF TASK 4 9 wow o9 v o9 DEFIME BEGINNING OF TASK 5 SKIP IF CHAMMEL NOT SELECTED INTERRUPTS OFF SELECT ORIGINAL WINDOW SET CURSOR TO PRINT MSS PRINT READING MESSAGE START A D ON CHANNEL WAIT FOR REPLY FROM ADC 1 SET UNUSED REPLY ASK FOR HIGH BYTE OF DATA WAIT FOR REPLY GET HIGH BYTE OF DATA NOT FINISHED A D YET ASK FOR LOW BYTE OF DATA WAIT UNTIL RECEIVED SET LOW BYTE OF DATA MASK FOR 4 DATA BITS USED COMBINE INTO TOTAL VALUE ee s IF BAND HBYTE 16 THEN RESULT RESULT CHECK NEGATIVE FLAG CURSOR 17 3 PRINT CURSOR 17 66 FPRINT IS Z RESULT SET CURSOR TO ERAGE MSS ERASE READING MESSAGE SET CURSOR TO PRINT VALUE PRINT VALUE READ 27 supported in the latest version of MT BASIC such as the on
66. NS eENVIRONMENT SAVE amp LOAD eMULTI SEGMENTED FOR LARGE APPLICATIONS eEXTENDED ADDRESSING eMEMORY ALLOCATION CONFIGURABLE ON LINE eAUTO LOAD SCREEN BOOT eLINE amp SCREEN EDITORS eDECOMPILER AND DEBUGGING AIDS 68088 ASSEMBLER SGRAPHICS amp SOUND eNGS ENHANCEMENTS eDETAILED MANUAL eINEXPENSIVE UPGRADES eNGS USER NEWSLETTER A COMPLETE FORTH DEVELOPMENT SYSTEM PRICES START AT 70 NEW HP 150 amp HP 110 VERSIONS AVAILABLE jun P NEXT GENERATION SYSTEMS P O BOX 2987 BANTA CLARA CA 95055 408 241 5909 are available that can acquire data at high speed and store it in an internal buffer releasing it to the computer later for processing Other kinds com municate with the computer in real time passing along each reading as it is taken and all the processing intelligen ce resides within the computer The Hardware With ADC systems like any other product the cost of the device depends alot on the features that it offers Since most ADCs do pretty much the same thing the range of prices depends more on HOW they do it The main con siderations are 1 Number of each kind of input or output 2 Resolution accuracy obtainable 3 Speed of analog sampling 4 Additional features such as BSR controller analog outputs memory buffers etc As in making any other kind of pur chasing decision the prospective user needs to analyze his needs and then to buy accordingly The
67. O ALLIANCE COMPUTERS PO BOX 408 CORONA NY 11368 POSTAGE AND INSURANCE INCLUDED 718 426 2960 All CPUS will be sent by Postal Service Ist cless insured or UPS Insured Please specify USPS or UPS UPS doesnt deliver to POBS Software will be sent by UPS Blue Label if you want UPS Next Day Air add 5 00 CPUs only Most all orders sent out same day COD add 3 00 APO s and FPO s welcomed N Foreign orders Please make payment in US dollars drawn on a US bank Add 5 for Registered Mail and Air Mail Postage except Canada No foreign COD s PLEASE INCLUDE YOUR PHONE NUMBER WITH ORDER S Resource Here s a catalog any serious computer tinkerer needs It s a treasure trove of stepper motors gear motors bearings gears power supplies lab items parts and pieces of mechanical and electrical assemblies science doo dads goofy things plus project boxes lamps lights switches computer furni ture and stuff you might have never realized you needed All at deep discounts cause they are surplus Published every couple of months and consecutive issues are completely different Send 1 00 for next three issues JERRYCO INC 601 Linden Place Evanston Illinois 60202 The Computer Journal Issue 21 One of the new developments is Structured Assembly Language Programming for the Z 80 from i Hayden Their approach is to use a large library which they supply on disk of macros for commonly used routines and then write
68. OGRAM AND CLOSE DATA FILE CURSOR 4 6 PRINT PRINT SAMPLING CHANNEL INPUT VALUE PRINT FLAS NUMBER LABEL TICS READ PRINT ene ee te PN ee Te e Pte ee Som Lem ERES IPRINT FOR I si TO 7 IF CHANNEL I 8 THEN PRINT PRINT GOTO 529 FPRINT X23 11 X8 829 X2 15 X7 14 2 I LABELS ID TKS D PRINT NEXT I tet UNSELECTED eco RUN 1 TIKSI RUN 2 TIKS2 RUN 3 TIKSI RUN 4 TIKSA RUN 5 TIKSS RUN 6 TIKS6 RUN 7 TIKS7 26 will prepare the program for another The Computer Journal Issue 21 538 RUN 8 66 test and telling it to read 0 samples will ee MR rum VIC RB KEYPRERGED quit 41 IF J 27 TMEN 543 IF lt ESC gt THEN QUIT 342 8070 549 OTHERWISE CONTINUE 543 CLOSE 1 CLOSE OUTPUT FILE Program Two LOGGER BAS 544 PRINT CONS ERAGE CURSOR BACK ON CLEAR SCREEN The second program is written in kp eee MTBASIC source code and to run it e MR MN 17 TO 7 TO READ ADC i ea must be compiled Because of its size it 70 THE ONBOARD CLOCK CARD MODIFY ACCORDING TO YOUR CARD 1 see IF IT IS NOT THE STANDARD KAYPRO CARD AND TASK 9 18 won t compile to memory and you will S99 USED TO WRITE DATA TO THE DISK BUFFER WHEN CHANNELS ARE need to use the DISK COMPILE option 688 READ THE DISK FILE IS SEQUENTIAL AND IT WILL BE UP 618 TO AN OUTPUT PROGRAM CRT OR REPORT TO FORMAT THE DATA of MTBASIC to produce an executable 620 ACCORDING TO CHANNEL NUMBERS TIMES OR OTHER PARAMETERS COM
69. Part B Conversion of units Part C Properties of materials finishes and surface texture including proper ties of steels heat treating terms har dness conversions and surface texture and roughness measurement Part D Useful shop data including drill sizes standard gages primary fits press fits bushing and shaft bore sizes Part E Fasteners including standards for inch size fasteners screw head dimensions strength of fasteners screws and pins pin standards and non metallic fasteners Section D2 Practical Design Hints Part A Machining minimizing machining effective clamping sim plifying machining with composit assemblies turning boring drilling milling broaching grinding and tap ping Part B Assembly avoiding over specification of dimensions of mating parts allowing for thermal expansion and wear designing for accesibility and ease of disassembly Section 1 Gear Design This section can help you understand the terms you will run into when specifying and or dering gears It covers involute curves pitch circles diametral pitch gear nomenclature pitch diameter and cen ter distance pressure angle helical gears spur gears racks internal gears worm gears bevel gearing strength materiais lubrication etc Section 2 Speed Reducers and Gear Trains While the previous section covered the subject of gears this sec tions covers two or more gears working together called a gear train Some o
70. RES MANAGE INDUSTRIAL PROCESSES MEASURE ENERGY CONSUMPTION CONTROL LAMPS AND APPLIANCES PROVIDE SECURITY PROTECTION PERFORM SCIENTIFIC DATA COLLECTION The ADC 1 serves as a real world interface for any computer or modem with a RS 232 serial port This sophisticated yet easy to operate data acquisition and control system includes 16 Analog to Digital Inputs 12 bits provide 0 1 mV resolution over 0 4V 4Digital Inputs for security and rotary encoder sensors e 6 Switched Outputs for relays and low voltage device control ACLine Carrier Transmitter controls 32 BSR X 10 type remote modules Owner s Manual with detailed programming examples Sensors available from Remote Measurement Systems include light temperature humidity wind sound soil moisture ultrasonic ranging energy consumption and security The ADC 1 an exceptional purchase at 449 REMOTE MEASUREMENT SYSTEMS INC 2633 Eastlake Ave E Suite 206 Seattle Washington 96102 328 2255 The Computer Journal Issue 21 brand new and incidentally very useful procedure called PrintAt at your disposal All that s needed is to in clude it into each source code as you write your programs Such pieces of source code can be in cluded automatically thanks to the compiler directive I the INCLUDE directive for the Turbo Pascal compiler To include the procedure PrintAt with another later progra
71. S9 a panel on 32 bit systems and on and on A sample of what you missed if you weren t there was the new Z80 replacement Hitachi s HD64180 Z80 Plus It was most unfortunate that the speaker at the SOG had only been in the United States for THREE days and his english therefore was rather poor This talk has since been supplemented with documentation which makes this new chip by Hitachi the HD64180 a real plus to the 8 bit world The unit is capable of addressing 512K of memory has two serial ports a timer DMA fun ctions and high speed clocked I O for chip to chip communications All this is placed on top of the 280 architecture and in CMOS for higher speeds 10MHz possible 8MHz nominal 6MHz now A Column by Bill Kibler and less power consumption The speaker was representing the MSC BOARDS imported by Southern Pacific Limited Box 4427 Berkeley CA 94704 0427 This company has produced a board having 512K of memory serial and parallel ports disk controller video controller and HD64180 all on a Five inch disk drive size board same as AMPRO As if the size and features were not enough the price was even better 400 and all available in a month or so If this product doesn t get Zilog to produce their long awaited Z800 nothing will The HD64180 has a few new instruc tions including an 8 bit multiply a sleep command and some special I O block moves Add this to their exten sions of the bit tes
72. Southern Pacific Turbo Pascal Handbook New Products Continued from page 43 HD64180 Communications Software Echelon Inc announces further sup port for Hitachi s HD64180 high integration 8 bit microprocessor chip with release of TERM III next generation communications software package which offers the following features Interactive communications with remote computer systems Reliable file transfer between the user s computer host and a remote computer Control of an auto dial auto answer modem Access control for remote system applications the user s system can be set up to be dialed into by outside users Rapid and easy reconfiguration of the communications environment for dif ferent applications Term III was designed to meet the communications needs of the serious Z System user and knowledge of that operating system is required to make effective use of the combination The program works with ZOPR3 and Z System and runs on Z 80 NSC800 and HD64180 based microcomputers Three books ZCRPS The Manual ZCPR3 and IOPs and ZRDOS Programmer s Manual provide detail descriptions of all Z System functions TERM III is priced at 99 and is available with the other Z System items from Echelon Inc 101 First Street Los Altos CA 94022 phone 415 948 3820 Technical Engineering BASIC TransEra has announced TBASIC a new technical BASIC for CAD scien tific and engineering applications
73. TASK SELECT FULL SCREEN WINDOW WAKE UP CLOCK CARD ASK FOR YEAR BET YEAR ASK FOR MONTH GET MONTH ASK FOR DAY GET DAY ASK FOR HOUR GET HOUR ASK FOR MINUTE GET MINUTE ASK FOR SECONDS GET SECONDS FPRINT I2 81 12 981 12 X2 12 81 12 81 12 Z MONTH 7 DQY 7 YEAR HOUR MINUTE SECOND INTON EXIT TASK 9 INTOFF IF K THEN 2798 FILE 1 gt INTERRUPTS BACK ON END OF TASK 8 DEFINE BEGINNING OF TASK 9 WHILE WRITING FILE NO INT WRITE ONLY IF A CHANNEL READ DIRECT OUTPUT TO FILE FPRINT 12 X3 12 X1 I2 X1 I2 X2 I2 X1 12 X1 12 X2 I4 SENSOR YEAR MONTH DAY HOUR MINUTE SECOND RESULT FILE Ke INTON EXIT wees DESELECT FILE INDICATE RECORD WRITTEN INTERRUPTS BACK ON END OF TASK 9 The Computer Journal Issue 21 Program 2 PROBRAM HISPEEDI e This program demonstrates high speed analog data acquisition with an ADC 1 system Rather than display data at once it simply stores data tO memory as it is read If wanted the readings are displayed as integer numbers and a calculation is made of the sample standard deviation In this way not only the speed but also the resolution of a data acquisition systse can be tested LABEL Start Stops TYPE Str Stringt8 4 VAR I J Value Code Channel Time X Stringt81t Buffer Arrayll 189898 of Integer StartSeconds StopSeconds Elapsed Samples Real Eleaent EleeentSquared
74. a subroutine with CODE statements and then access it with a GOSUB The most likely of the current languages for the Handler is Forth with a special dictionary of machine language subroutines for the speed critical routines but I can t seem to get started in Forth The concept of the language is easy to understand my problem is taking the time to learn to use the nonconventional editing file saving and user interface It would help if there was a local Forth advocate who could take the time to get me star ted Perhaps one of our readers would like to write an article on getting star ted with Forth not a description of the language but the mechanics of doing something with it UPGRADE THAT TIRED 6502 TO 16 BITS li 65802 CPU 49 95 16 bit version of the 6502 Pin for pin and completely software compatible with the 6502 CPU You can upgrade your Applel l L HIJI or c toa 16 bit computer simply by replacing the 6502 with the 65802 without losing the ability to run any old software ProDOS ORCA M ist 79 95 69 95 This ProDOS version of ORCA M comes with the complete 65602 Instruction set If you intend to develope software for this new CPU then this package is a must Chosen by the designers of the 65802 as the standard 65802 assembler se IE 109 95 yee This package includes 65802 CPU end the ProDOS ORCA M All you need to start FORTH PASCAL P code Upgrade amp MORE TO ORDER SEND CHECK OR MONEY ORDER T
75. ample rate is 7 5 sec RS 232 495 WB 31 White Box Interface Omega Engineering Inc One Omega Drive Stamford CT 986997 283 324 FLOW 2 analog inputs of 12 bit resolution 4 digital outputs A D sample rate 7 5 sec RS 232 395 Other models to 2999 Omega has a fine catalog of sensors that is well worth requesting 12232 Data Acquisition amp Control System Starbuck Data Company PO Box 24 Newton Lower Falls MA 2162 617 237 7695 Microprocessor controlled 8 analog inputs of 12 bit resolution 8 digital inputs 8 digital outputs RAM to store 2000 data points of burst data 699 Analog 8 bit 8832 version is now 399 The Computer Journal Issue 21 ANALOGIN sends a command byte that represents the channel number 1 which tells the ADC 1 to start digitizing that channel The terminal strips are labeled 1 16 and people tend to think that way too but the ADC 1 is expecting a value from 0 15 The next step is to assign HighByte the value returned from the ADC 1 when the command 161 is sent to it The bit that represents the binary number 128 is checked until it is a 0 indicating that digitizing is complete Then it s safe to read the LowByte with a command of 145 Only the 4 LSB of HighByte contain data the rest are status so HighByte is ANDed with 15 to result in the variable MaskedHighByte From here it s a simple matter of multiplying the masked high byte by 256 and adding
76. any others If you already have a routine written to get the time and date from your system clock just insert them in place of these To convert these procedures for another system refer to TASK 8 in Program Two where the function of each port is commented in more detail FUNCTIONS GETDATA and ANALOGIN are used together to send a command to the ADC 1 and to get a complete byte back from it I write these as separate functions because GETDATA is also needed with fun ctions that read the digital inputs and send commands to the BSR transmitter of the ADC 1 system They could of course be combined into a single fun etion To see how they work look first at ANALOGIN Since it calls GET DATA ANALOGIN must come second in the listing ANALOGIN is a function to which a channel number is passed as a parameter and which returns an in teger value the reading from that channel to the calling routine Because the ADC 1 provides 12 bit resolution the answer can t be obtained in one 8 bit byte and two are used HighByte contains the 4 MSB most significant bits of the data plus other bits that in dicate polarity whether the A D con version is finished and an over range indication LowByte contains the 8 LSB least significant bits of the analog value at the channel Now it s time to take a look at GETDATA GETDATA also uses a parameter the byte to be sent as a command to the ADC 1 The answer byte is the value that is sto
77. area circumference centroid and other calculations for polygons Other features include line labels block IF statements true sub Continued on page 51 DON T PAY 700 FOR DATA ACQUISITION SOFTWARE We offer full featured reasonably priced data logging software Our Software is well documented unpro tected and fully listable 64 CHANNEL CAPACITY DATA LOGGING PACKAGE for IBM PC 150 128 CHANNEL CAPACITY DATA LOGGING PACKAGE for APPLE lie HARDWARE SUPPORTED IBM Model 140 15 bit A D 7 5 samisec APPLE Model 34 12 bit A D 40 000 samisec Model 38 8 bit A D 111 000 samisec Model 14 13 bit A D 15 sam sec Model 40 Timer Clock 1 ms resolution BOTH Model 20 Difterential Thermocouple Thermometer with true cold junction compensation 175 Model 17 16 channel differ ential Multiplexer 165 LAWSON LABS INC 5700 Raibe Road Columbia Falls MT 59912 Phone 406 387 5355 The Computer Journal Issue 21 problem if you haven t assembled your own Forth compiler While figuring out how it is done I also considered writing or designing my own language as the structure and concept are pretty sim ple Forth is most confusing only due to the use of the cryptic words For those like myself who mostly do assembly work we have already learned all the three letter codes that represent data movements in assembly Forth words are no different than these and the comparison can be used to help under
78. at we can choose the best language for each application There isn t and never will be a perfect language which is optimum for every use When we learn our first language we think that we can do everything with it and although it is cumbersome for some uses we plod along because we don t want to give up our hard won skills and start over again with a new language But learning the second language is a lot easier than the first j one and it enables us to see how clunky the first one was in some areas and also how we miss some of its features in the new one If you haven t already read Kibler s Computer Corner turn to the back page and read it now because Bill s thoughts about languages have been voiced by others several times during the past two months Assembly is a great programming language and the small ROMable programs run fast but coding can be tedious for large programs and I O screen handling menus and floating point math routines can be a real bitch to code Developing a non trivial assembly language program is awk ward because you have to write the souce code with an editor I use Wor dStar assemble to a HEX file and load that to a COM file for a trial run Then back to the editor for any revisions and through the whole routine again An assembly language program is also VERY difficult to understand and up date in the future even if you wrote it yourself and can be almost impossible
79. ath functions are done in the main kernal with more advanced functions calling these routines The ROM code of course doesn t have any buffer spaces inside the ROM Other than that it would be the same as regular Forth code While this con cept is pretty well known the actual putting of code into ROM can still be a
80. can quickly isolate the bad components Otherwise if unfamiliar with a circuit you may wind up unsoldering five six seven or more IC s before achieving a fix Clearly if the IC s are in sockets the repair process will proceed far quicker and easier Printed Circuit Boards The Inside Story It may seem out of place to talk about circuit boards in this article when the next will be all about repairing them but since unsoldering failures are the chief cause for needing to repair them it s useful to briefly discuss them so as to limit the potential problems Ac tually we re going to talk about geography and social issues that may seem to have nothing do with our prime subject but in fact they do In North America most circuit boar ds are manufactured not by the kit makers or product assemblers but by specialized firms that act as subcon tractors Many of the boards these fir ms produce are destined for products that will be used by the Military When circuit boards first appeared the Military tested them under the harsh conditions their equipment must en dure and the early boards failed miserably however the potential benefits of boards led makers to develop types that could stand up to Military testing Eventually these types were approved and a set of specifications called Mil Specs defines how these boards are to be made Typically these boards use glass filled epoxy construction techniques which require sp
81. ce oin rcc ewe E pa usd 99 95 Elegant menu and command line driven file and disk catalog manager DISCAT Generates and controls multiple master catalogs working catalog used for update quickness Nine flexible modules easily altered by user for custom requirements Works with Z shells VMENU VFILER MENU aliases and multiple commands per liie sor Ee ore aue EE I use pe wi tre ye vraie a wets S efe e 39 99 ZCPR3 The Manual Bound 350 pages typeset book describes features of ZCPR3 command processor how it works how to install and detailed command usage Bible to understand Z System eeeeseeeee eee 19 95 ZCPR3 and 1 OPS Loose leaf book 50 pages 8 1 2 by 11 describes ins and outs of input output processing using Z System Shows how to modify your BIOS to include VO redirection complements The Manual veeeee eee 9 95 More missing links found Z Application Progams Fly with eagles Our programs promote high performance through flexibility Productivity results from dynamically changeable work environments matching operator to tasks and machines Above programs require 48K byte memory ZCPR3 Z Com or Z System and Z80 NSC800 HD64180 based computer Shipping from stock State desired disk format plus two acceptable alternatives AS payment we accept Visa Mastercard personal checks money orders and purchase orders from established companies We also ship UPS COD Call or write to place
82. ced features SOFTAID Inc Features Multitasking Windowing Interactive Compiles in seconds Multi line functions No runtime fee Handles interrupts Fast native code ROMable code Formatted I O Assembly language calls In line machine code P O Box 2412 Columbia MD 21045 1412 NYT NS aiu WASEDA uos title eee ot Mee sen Complete Package The MTBASIC package includes all the necessary software to run in inter preter or compiler mode an installation program so any system can use win dows demonstration programs and a comprehensive manual Ordering MTBASIC is available for CP M MS DOS and PC DOS systems for 49 95 MTBASIC with 8087 support is available for MS DOS for 79 95 Shipping is 3 50 10 00 overseas MD residents add 5 sales tax MC Visa checks and COD accepted 301 792 8096 The Computer Journal Issue 21 spring loaded sucker with an iron It s so new that Radio Shack hasn t cap tured one yet OK Industries Inc lists one in their catalog Model SA 8 This looks as though it might work well it would seem to handle easily has a small tip opening and the snappy action of a spring sucker Only drawback is that these tools cost between 25 and 35 depending on where you spot it this would make it a tool for the serious unsolderer Having covered the major types of solder suckers we move on to the other method of removing solder wicking Because we make the solder into a liqu
83. continued selling individual copies of uninstalled CPIM and will only sell to hardware OEMs who will ship installed versions with their hardware How can you obtain an operating system for a Z 80 or HD64180 single board computer you design You either pirate CP M and end up with an illegal unsupported system or you find another supplier better choice than CP M even if it was available is the Z System from Echelon because it can do so much more than CP M and it is sup ported by people who care about YOU youl ments matching operator tasks and machine developed Muitipie Commands per line Auto disk reset when changing floppies rnore easily added 76 syntax compatible support utilities the user It is time to change to an im proved up to date supported system even if you already have CP M up and running Write to Frank at Echelon 101 First Street Suite 427 Los Altos CA 94002 for information on the Z System And if you implement it for a new application share the BIOS with other readers We Are The Pioneers of the Future What will computers be like five years from now Predicting the future for computers is very difficult If you doubt it check some of the forecasts made five years ago and see how off base they were I ll stick my neck out and make a forecast for the state of microcomputers in the year 1991 I Z SETS YOU Z Operating System an 8 bit OS that flies Optimized HD64180 Z
84. control his heat pump home security system and other devices in the same way His suc cess in controlling his environment has prompted him to develop and market such systems to aid other handicapped persons using the Corona PC when voice actuation is required and the Commodore 64 as a lower cost alter native for those cases in which the user is able to operate a standard keyboard 6 A grower of miniature roses in Seattle uses a Radio Shack Model 100 portable computer and an ADC to monitor and control his commercial greenhouse Analog sensors monitor soil moisture soil and air tem peratures relative humidity and light BLANKENSHIP BASIC GIVES YOU JE emer ware MORE DOS 3 3 VERSION 25 OR PRODOS VER BOTH FOR 39 95 ADD 2 00 POSTAGE AND HANDLING 10 DAY MONEY BACK GUARANTEE APPLE ie o regieterd tredegsark of APPLE 2mputer Iac Real interpreter not a pre processor WHILE ENDWHILE and REPRAT UNTIL loops True IF THEN ELSE ENDIF using WHEN PRINT USING FILE MERGE RANDOMIZE PRINT and TAB commands work in HIRES 80 columns supported on le and Ic Full editor with AUTO NUM and RENUM Fast SORT SEARCH and INSTR commands BOX BOXFILL DRAN USING and SOUND Listings are indented automatically DISK command replaces DOS s CHR 4 DEFINE and PERFORM named procedures 99 upward compatible with Appiesoft All commands entered normally no k s 100 s of satisfied users world wide FREE newslet
85. d above If heating a joint and pulling things apart is not always practical then the next step would be to remove the solder Since solder invades the surface of the metals it is not possible to remove it all but if only the surfacetoating remains then the resulting joint will be ex tremely weak and should fracture like the hide glue with gentle manipulation Clearly we can t simply swab up molten solder with a Q tip or even the quicker picker upper a paper towel hot solder would burn these materials and being organic they would not readily absorb a hot metal We could use some sort of wick to absorb the solder as long as the wick is compatible with solder and later we will talk about such products Another approach would The Computer Journal Issue 21 be to vacuum it up with a wet dry vacuum cleaner which would indeed work but is actually a bit too elaborate Instead there is a whole array of tools ranging from the super simple to ut terly elaborate that use vacuum to suck up the liquefied solder Tools and Techniques The first tool we ll discuss is the soldering iron used to reheat the joint No mystery here simply select the same size iron and style of tip as you would have used to make the connec tion see the first article in this series for details To use the iron first heat it up and properly tin it then apply it to the joint so that it touches the lead and sits on top of the solder fillet This causes the
86. e at 190 210 which converts BCD numbers into ASCII numbers as did FUNCTION ACD in Program One Lines 216 218 initialize an array of channel flags to zero which flags will later be used to indicate which channel has just been read MTBASIC supports multiple instruc tions on a physical line using semicolon separators but using short lines like these leaves plenty of room for good documentation and I ll recommend easier to follow code every time Significantly the compiler does NOT translate the comments so there is no efficiency advantage to be gained by leaving them out and no real excuse to pack as many instructions on as few lines as possible The statements at 225 230 create two strings that are the escape sequences to turn off the Kaypro cursor These might need to be translated for another computer or left out entirely if that feature is not supported Notice that it isn t possible to concatenate strings using the operator as in most versions of BASIC The CONCATS function must be used each time one string is added to another Turning off the cur sor provides a cleaner screen display and is recommended CAUTION Remember to turn the cursor ON at the end of the program or you may have to re boot to get it back The actual purpose of the rest of the code is pretty obvious from the com ments so I ll concentrate on explaining the workings of MTBASIC where it differs substantially from other ver sions The fi
87. e cost of sockets is almost in significant especially when weighed against the convenience they provide From this it might seem that you should always use sockets some people including myself would take this position others hold opposing views and it may be worthwhile to delve a lit tle deeper into the reasons for the con troversy There are some additional and subtle reasons why commercial builders omit Sockets If you read the article on soldering you may remember the part about how corrosion affects all metals It happens that soldering a connection almost entirely eliminates that danger a soldered joint is considered in the trade gas tight that is unaffected by the oxygen and other contaminants in the air Wire wrapping and some other connection methods also produce gas EMILIA T 4424252444 t E deh a E ee weevecsess The Computer Journal Issue 21 tight joints But the junction between an IC s pins and a socket s metal are not truly gas tight When sockets first came into use they were particularly prone to this problem and earned a reputation for unreliability Socket manufacturers responded to this by making a whole series of im provements They designed better con tact points and then they re designed them again until today each socket maker trumpets the effectiveness of their design They began to gold plate the contact points gold being ex tremely resistant to corrosion All these steps taken
88. e that ends in a pointed hollow tip about the size of a circuit pad Here s how to use it if you re right handed hold the bulb in your left hand and squeeze it closed lefties use your right hand you ll hear Figure 1 Solder Suckers from left to right a simple type a spring type acombination of iron and built in bulb air being expelled out the tip keep it closed With the soldering iron in your other hand apply it as described above Once the solder is liquid in one quick smooth motion remove the iron and with your left hand place the tip of the solder sucker over the joint and im mediately release the bulb Let it spring open quickly this will create a vacuum at the tip and suck up the molten solder Sounds simple but the process is ac tually easier to describe than to accom plish on the first attempt Two waysto overcome this first find someone who knows how to do this and have them teach you just watching is very helpful or find a scrap printed circuit board and practice the technique several times until you master it The bulb type solder sucker is a very simple tool and has few problems Oc casionally it will fill up with bits of solidified solder and must be cleaned To do this just hold it over a trash can and pump the bulb to blow the pieces of solder out if they are too large to fall out then twist off the tip and shake them out of the bulb The tip itself is made of a coated plastic and solder par
89. ecial manufacturing procedures but the resulting boards are very durable indeed Most circuit board makers must be able to produce Mil Spec boards and find it economical to only produce that type which means that even if a company doesn t need gt s at fast S je ren P MVWRIM EP jo 33 such rugged boards they will get them anyways and it won t cost extra If a circuit board was made in North America then chances are it is of epoxy type construction and can withstand unsoldering heat very well also the traces will adhere a little better thus reducing the chance of delamination These boards often seem able to withstand an M 1 Tank In the Far East which is the other great source of products with circuit boards there is almost no need to meet Mil Specs and most product makers produce their own boards They make boards the old fashioned way which is a paper laminating technique These boards stand up well to consumer use but not so well to unsoldering heat It s quite easy to delaminate both the traces and even the board itself by using too heavy a hand with the iron What we said above is only a generalization both types of boards are produced in both places so knowing the origin of a board is just the first step in identifying its construction Epoxy boards are usually a light beige color in their raw state but more likely are green or blue due to an applied solder mask Paper laminate boards are often 0 to
90. edious wirewrap ing or soldering techniques A must or every designer Only 404 928 9394 44 Editor Continued from page 1 changes until it works They also design i languages which require many steps and considerable time between the writing of the code and execution of the program While this approach may be acceptable for business related ap plications where the desired result is know in advance it is not suitable for experimental work such as robotics or control where the program is a tool and not the final result What I would like is a programming tool should it be called a language that is easy to program generates small ROMable fast acting code is in teractive and can be customized or ex tended by the user I m looking at this from the point of a user who has to program in order to accomplish their goal in a fast changing experimental situation instead of a programmer who is writing code for a canned program to be used by someone else I haven t had the time to fully define what I want but I ll list some initial thoughts hoping that you ll add your input Perhaps we can generate enough in terest to start a special user s group to work on this project I would like to be able to write sec tions in assembly language add them to a library and call only the required routines from a higher level language which I ll refer to as the Handler This sounds like a Macro Assembler but I was thinking of
91. em about a little more vigorously and occasionally the three hand method helps Staking is done to IC s two or more leads usually at diagonal ends are bent over flat against the pad to lock the IC into place Once soldered the staked pins are really tough nuts to crack To deal with them first proceed to un solder all the pins as you normally would in the case of the staked leads remove all the solder you can from on top of them Because of the staking they will still be firmly anchored To free them mount the board in your holder and take a small X acto or utility knife in one hand and your soldering iron in the other Apply the iron over the pin holding the knife so that you can slip it under the staked over pin as the solder liquefies Merely slip the knife under and lift a little remove the iron wiggle the knife slightly so the solder bond doesn t reat tach Use the greatest of care when at tempting this procedure you ll be using a sharp knife and a hot iron plan your moves so that if you slip neither knife or iron is likely to injure your hands Absolutely wear eye protection even better wear a face shield if you have one Next take a small screwdriver and very slowly bend the lead into an upright position bend too fast and the lead will fatigue and break Use a good desoldering tool to clean out the hole you may need to use the techniques described for stubborn joints For various reasons staking is becoming ra
92. en Where line 670 says CURSOR 9 3 it is positioning the cursor within the WINDOW being used not the entire screen In this program it amounts to the same thing but the distinction is important in programs that use several windows Again the processing logic is well documented in the source code so I ll comment here on the MTBASIC syntax Line 730 uses the BAND bit logical and function to check the byte at the status port INP 6 for the Kaypro If bit 1 is 0 a complete byte hasn t been received at the serial port FPRINT is used again in line 850 printing the RESULT in a 5 character integer for mat with a carriage return at the end the Z Each of these seven tasks prints a message such as READING beside the screen line for that channel letting the user know when a particular chan nelis being read Then it gets the value from the ADC and prints that in its The Computer Journal Issue 21 proper place on the same line Line 880 turns on the flag K in dicating that a channel has been read and places the channel number in the variable SENSOR These values are used by the task that writes to the disk file Task 8 reads the Kaypro clock card and again the comments show what each line is meant to do This task would need to be modified maybe a lit tle maybe a lot to read from a different clock Task 9 writes to the disk file Since RESULT is used by all the analog read tasks and since the proper channel
93. equally well Since you ll be grasping the IC by its plastic body you should be able to use your fingers and if the body gets so hot as to burn your fingers then you ve overheated the IC You could also use a tool to grasp the IC the Radio Shack IC Extractor is fine or you can make one from scrap metal by studying the basic idea Grasp the IC so that you can exert firm but even pull on it apply the soldering iron to the recalcitrant joint and as it liquefies start pulling Even when two stubborn joints are involved if they are on opposite sides of the IC then you ll be able to free one side and then do the other Afterwards you ll need to bend the leads back into shape The Computer Journal Issue 21 but that s easy if you work slowly The same method can also be used with stubborn resistors capacitors etc 4 Crimping and Staking Some circuit boards needing repair may have been assembled using these industrial techniques When the com ponents are mounted on the boards by hand prior to a one step soldering process such as dip or wave soldering crimping and staking serve to keep the parts from falling out while in process Unsoldering those parts later can prove extra difficult Crimping is done to small two lead parts a special forming tool bends the leads so that when the part is inserted a high degree of friction with the board holes keeps it in place To remove these parts is not too hard you may to need wiggle th
94. ew from Pickles and Trout in 1979 and used once 100 Call Phil Wells at 406 755 1323 days or 406 844 3240 evenings Corvus 10MB Hard Disk for the Apple II plus 888 00 Apple III Second Disk Drive 199 00 Apple III SOS Device Driver Writer s Guide 19 95 BPI Accounting for Apple III Requires Hard Disk 99 00 Apple Writer 1 1 16 Sector 8 88 Apple DOS User s Manual II II plus Ie 8 88 Apple DOS Programmer s Manual II II plus Ie 6 88 KAYPRO Home Accountant by Con tinental 49 00 Soroc IQ 130 Terminal 399 00 All plus shipping The Computer Place 36 2nd Street East Kalispell MT 59901 Phone 406 755 1323 THE SECURITY DISK PROTECTED VS UNPROTECTED At last the best of both worlds Here is software designed to PROTECT YOUR PRIVATE FILES SIM PLE PROTECTION TO MULTI LEVEL CRYPTOLOGY Plus DYSUN THE DISK UNLOCKER WILL ANALYZE amp UNLOCK COMMERCIAL COPY PROTECTED DISKS then recopy them to standard DOS 3 3 format DYSUN will also RECOVER LOST DATA amp REPAIR BLOWN DISKS A special SECRETS TIPS TECHNIQUES program is also in cluded Not locked up Listable Machine Language Source Codes included Supports Apple II II Plus IIc Ie To order send 29 95 CHECK MO to B M E Enterprises Box 191 J Kila MT 59920 Book Sale These books are offered at this price while the supply lasts Zilog Z80 CPU Technical Manual 1 50 CBASIC Users Guide by Osborne Eubanks and MeNi
95. f COUNT will be stored separately and will exist ONLY to the procedure in which it is declared an example of local scope If however I declare a variable called COUNT at the beginning of the program then it s fair game for each procedure in the program Any of them can change its value and only ONE version of it exists in memory It s easy to see that there are good uses for local variables just as there are good reasons to use global variables depen ding on the logic of the program Procedures All implementations of Pascal in cluding Turbo Pascal depend heavily upon procedures which are sections of code that are written to accomplish a particular task One of the greatest strengths of Pascal as a language is that it encourages the thoughtful design of a program through top down structuring techniques as mentioned above Another strength is that procedures once properly written can be used again and again in programs that require the same simple task Since procedures are called when needed just by mentioning their name the language itself can be extended in any way the programmer desires Con sider the case of GOTOXY It s a fun ction that s provided with Pascal one the user doesn t have to write and is part of the Pascal Library runtime package that becomes a part of each program when it s compiled GOTOXY positions the cursor on the screen so that a non scrolling display can be writ ten The hori
96. f the topics are simple spur gear trains compound spur gear trains planetary gears bevel gear differentials force transmission tangential forces power flow efficiency minimization of gear train inertia backlash transmission error configurations and designs limit stops etc Section 3 Basic Electricity brief section on AC circuits fundamental laws and three phase power Section 4 Motors Part A Design con siderations motor characteristics selecting gear motors motor speed controls Part B Escap ironless rotor DC micromotors and step motors physical laws governing Escap motor applications basic motor physics gear boxes control of DC micromotors tutorial on micromotor application problems Escap step motors Part C Step motors principal types primary step motor performance charac teristics damping step motor driving and control considerations for step motor applications Section 5 Negator constant force springs and spring motors Design stock parts saftey considerations Section 6 Couplings and Universal Joints Types of flexible couplings kinematics joint selection torque rating secondary couples joints in series Section 7 Drives Part A belt and chain drives V belt design data roller chain design data center distances lubrication tensioning mechanisims Part B synchronous belt drives belt tooth configurations pully pitch design and installation standards drive ratio
97. f some kind and has meaning only because it relates to some observable physical phenomenon that we can perceive If we hear from an astronomer that the normal temperature on the surface ofa certain planet is 300 Kelvin most of us would have learned very little If the same astronomer then says by the way water freezes at 273 K and boils at 373 K suddenly that first statement means a lot more Without doing a lot of tricky math it s easy to see that 300 K is comfortably above freezing and a long way from boiling phenomena that we all under stand Analog information is everywhere we look If we glance at the speedometer we don t want to know whether we re moving or not we want to know how fast It doesn t help to know that there s water in a swimming hole before we dive in we need to know how deep A computer can do some remarkable things if it s able to gather analog data from its environment and if that data is converted into a digital form the com puter can deal with Knowing how dry the lawn is the computer can decide when to turn on the sprinklers Knowing how bright the sun is the computer can open the drapes in the winter or close them in the summer How fast a drill is sinking into the ground can be important to an oil well driller Actually there are few fields of en deavor that can t benefit from com puter automation now that chips are cheap and you guessed it easy to
98. features men tioned above Also some manufac turers are responsive to custom orders and make options available when needed An ADC that normally includes six controlled outputs and a BSR tran smitter is also available with twelve controlled outputs and no transmitter People working in the field with no way to use BSR modules sometimes opt for the additional outputs Some companies offer the ultimate in options intelligent microprocessor controlled data acquisition and control systems designed and built just fora particular task With no need for a supervising computer such systems can be very inexpensive in reasonable quantities If your needs are of an OEM nature or your application requires a number of systems ask if one can be built to your specifications Applications The following applications are all made possible by a data acquisition and control system In most cases the programmers involved are NOT com puter professionals but specialists in their own particular fields They re able to program their computers to make the necessary decisions and that s pretty much all that s needed Some of these uses for Real World computing may suggest ways that an ADC system could make your life easier 1 WSB TV in Atlanta uses a Com modore 64 to collect meteorological data from 13 remote weather stations in the surrounding region to provide detailed reports of current conditions Each station consists of a modem an
99. ff 14 00 Introduction to FORTH by Ken Knecht 9 00 FORTH Programming by Leo J Scanlon 13 00 These prices are postpaid in the U S only TCJ 190 Sullivan Crossroad Columbia Falls MT 59912 COMMODORE 64 INTERFACING BLUE BOOK Build 36 useful interfaces for your computer 196 pages Complete detailed in formation Satisfaction guaranteed 16 95 postpaid Microsignal Press PO Box 388 Goleta CA 93116 CMOS PROTOYTPING SYSTEM Uses NSC 800 I C for Z 80 Compatibility 4 STD Bus Cards Dual Serial I O CPU 32K Static Memory 24 bit Parallel LO battery powered 6 slot card cage and standalone debugging monitor Mates with Industrial I O Racks Opto22 DuTech etc Complete package only 795 plus S amp H originally cost over 1200 Brochure sent on request Input Video PO Box 20 Randolph MA 02368 phone 617 961 4197 STD Bus Cards Wide assortment of STD Bus cards CPU s Memories Static amp Dynamic types Serial I Os CRT con trollers etc Quantities limited send SASE for complete listing and prices Input Video PO Box 20 Randolph MA 02368 phone 617 961 4197 50 Advertiser s Index John Bell Bersearch Blankenship Basic BY Engineering Classifieds Computer Trader Digital Images Echelon Inc Miller Microcomputer Services Micromotion Micro Systems Research Next Generation Systems Poor Person Software Public Domain Software Remote Measurement SC Software SLR Systems Softaid
100. file from it The multitasking reo ES PINE men hard Q TEC feature of MTBASIC makes it easy to Ne Eee EE SETE write a general purpose analog data 660 NSELECT 8 BELECT ORIGINAL WINDOW 478 CURSOR 9 3 SET CURSOR TO PRINT MBG logging program like this One of the 686 PRINT gt gt READING gt gt PRINT READING MESSAGE i 1 i 698 OUT 4 0 START A D ON CHANNEL t nme available tasks 19 used to read the 766 IF BAND INP 6 1 8 THEN 796 WAIT FOR REPLY FROM ADC 1 system clock and another is used to log 718 CHARIN INP A GET UNUSED REPLY 7 T 4 161 ASK FOR HIGH BYTE OF DATA data to the disk file so that leaves e Y BOMD INP D 1 8 THEN 738 WAIT FOR REPLY 748 HBYTE INP 4 GET HIGH BYTE OF DATA soven analog channels that can be read 759 IF BAND HBYTE 128 THEN 726 NOT FINISHED A D YET each according to its own schedule 768 OUT 4 145 ASK FOR LOW BYTE OF DATA n 77 BAND P 6 Ti 778 WAIT UNT RECET Many people are not yet familiar 706 Lovie wal EP GET LOW BYTE or DATA 1 i i 798 HMASK BANDIHBYTE 15 MASK FOR 4 DATA BITS USED with using MTBASIC though it has 866 RESULT LBYTE 256 HMASK COMBINE INTO TOTAL VALUE been the subject of a review in The 818 IF BAND HBYTE 16 6 THEN RESULT RESULT CHECK NEGATIVE FLAG A 8208 CURSOR 9 3 SET CURSOR TO ERASE M58 Computer Journal so I ll mention as I B3 PRINT ERASE READING MESSAGE i i 8409 CURSOR 9 66 SET CURSOR TO PRINT VALUE go some of the thing
101. h features are not part of Pascal because the code required to execute them would become part of every compiled program including the thousands of programs that never have to perform such tasks It s at times like this that the exten sibility of Pascal really comes through Here s a function called POWER that will provide the same feature in Pascal Function Power X Y Integer In teger Var R Real Begin R Exp Ln X Y Power Round R End The first line names the function just as we named a procedure in the PrintAt example In the parentheses are defined variables representing the two values that will be passed to this fun ction the parameters Variables X and Y are to be integers as is the function Power itself The local variable R for result is assigned as a Real R is arrived at using the EXP exponent and LN natural logarithm functions which are built in Then R is rounded off and stored in the function Power This function was writ ten for the purpose of setting and clearing bits within a byte so it was designed as an integer function It could easily be rewritten as a real function for floating point math Again the BASIC code A B C can be duplicated in Pascal as A Power B C and once more the language has been extended with the addition of a new keyword Portability In this case portability refers to the quality that lets a function or procedure be used with any prog
102. h as analog digital data acquisition programs I keep a special version of STARTUP PAS that con tains in addition functions and procedures for opesating an ADC 1 Data Acquisition and Control System On disks I use for business programs I keep a copy of STARTUP PAS that in cludes procedures and functions for getting dates and times from the clock card printing datelines and soon W The following are Registered Trademarks Turbo Pascal Borland In ternational MBASIC Microsoft Ap plesoft Apple Computer Company WordStar MicroPro International CPIM 80 C Programmers Save time With the BDS C Compiler Compile link and execute faster than you ever thought possible If you re a C language programmer whose patience is wearing thin who wants to spend your valuable time programming instead of twiddling your thumbs waiting for slow compilers who just wants to work fast then it s time you programmed with the BDS C Compiler BDS C is designed for CP M 80 and provides users with quick clean software development with emphasis on Systems programming BDS C features include Ultra fast compilation linkage and execution that produce directly executable 80801280 CP M command files A comprehensive debugger that traces program execution and interactively displays both local and external varrables by name and proper type Dynamic overlays that allow for run time segmentation of programs too large to fi
103. hat they won t scratch if slid along on a circuit board Now using a screwdriver with a blade just about the width of an IC s pin place it against the board next to an IC pin Holding it down so it won t jump over the pin push gently inwards with just enough force to break the weak solder bond inside the hole You ll know this has happened because the pin will suddenly give way and then you ll see THE BEST Z80 ASSEMBLER ON THE MARKET JUST GOT BETTER 15 that it can be wiggled back and forth in side the hole This technique requires great care and a lot of practice to learn just the appropriate amount of force but it is necessary Without this step you ll probably be unable to pry the IC off the board without breaking the IC and lifting some traces Sometimes as you attempt the first few pins on an IC you find that too much force is needed and instead of freeing the pin the screwdriver slips over it perhaps even bending it down when this happens I use an extra step that usually helps Take some solder wick as thin a width as you have and place it next to the pin just like the screwdriver blade then with the hot soldering iron press in gently Let the heat of the iron do most of the work The pin should move inwards in a few seconds and the wick will pull out the residual solder After this the screwdriver should easily free up each pin So little solder is involved that you can slide the iron along the wick as you do each pi
104. heat to flow through the lead into the hole and on to any solder on the other side of the board This is impor tant when working on double sided boards and works just as well on single sided ones The solder fillet will tell you when it s molten because the tip will slip down into it Keep the iron in place for one second more and the joint is all set for the next step Occasionally it won t be possible to position the iron as described in that case apply the iron as best you can for no more than about one second longer than would be needed to make the connection Be very careful not to overheat the connection if it doesn t seem to be liquefying back off and evaluate the situation before trying again Do you recall those vague allusions to strange hand grasps at the start of this article The time has arrived to reveal all as we delve into the arcana world of the Solder Suckers No these are not a lonely band of misguided con sumers who bought the wrong type of solder rather they are tools There are three distinct classes with numerous subspecies but they all share the com mon characteristic of providing a small rapid vacuum that pulls the molten solder out of the joint In true zoological fashion lets begin by examining the ancestral Solder Sucker which is by no means extinct You can find this primitve at your local Radio Shack Cat No 64 2086 All this tool consists of is a rubber bulb at tached to a plastic tub
105. his tool has some drawbacks First the iron has a hefty wattage rating 45 Watts for the Radio Shack model and can cause damage to circuit traces if you re not careful Secondly the tip is usually wider than the standard pad size of a circuit board this forces you to slide the tip until one part makes con tact with the protruding lead unfor tunately this often inteferes with com plete cleaning of the circuit board hole And lastly it can be rather awkward to operate the bulb you just can t seem to develop as much vacuum as with the simple standalone bulb and nowhere as much as the spring type tool There is _ one instance where this tool is helpful it occurs when attempting to desolder a DIP and will be discussed later under the mechanical aspects of unsoldering And for those who may not believe solder suckers evolve a new member of the family has been sighted in the last year or two This type combines the PF iindowing Multitasking ROMable code Multi line functions MTBASIC the multitasking Basic compiler has everything you need Interactive Compiler MTBASIC is an interactive compiler and a unique Basic language MTBASIC is easv to use since vou can write pro grams in an interactive environment and them compile them using only one com mand MTBASIC is easy to learn because it is similar to manv other Basics The biggest advantage of using a compiled Basic is FAST PROGRAMS With MTBASIC vou get speed and advan
106. icro e The Computer Corner Interfacing Tips and Troubles Memory Mapped I O on the ZX81 issue Number 18 e Interfacing the Apple II Parallel interface for the game port e The Hacker s MAC A letter E from Lee Felsenstein e S 100 Graphics Screen Dump e The LS 100 Disk Simulator Kit A product review e BASE Part Six e Interfacing Tips amp Troubles Communicating with Telephone Tone Control e The Computer Corner The Computer Journal Tssue 21 Issue Number 19 Using The Extensibility of FORTH Extended CBIOS A 500 Superbrain Computer Base Part Seven i Interfacing Tips amp Troubles Part Two Communicating with Telephone Tone Control e Multitasking and Windows with CPIM A review of MTBASIC The Computer Corner Issue Number 20 49 Build the Circuit Designer 1 MPB Designing a 8035 SBC Using Apple il Graphics from CP M Turbo Pascal Controis Apple Graphics Soldering and Other Strange Tales Bulld a S 100 Floppy Disk Controller WD2797 Controller for CP M 88K The Computer Corner Ordering Information Back issues are 3 25 in the U S and Canada Send payment with your complete name and address to The Computer Journal 190 Sullivan Crossroad Columbia Falls MT 59912 Allow 3 to 4 weeks for delivery Classified Classified ads are 25 cents per word All Classified ads must be paid in advance and will be published in the next available issue No checking copies of
107. id by heating it we can also wick it up just like a candle wick or a kerosene heater wick For solder we need something that solder will stick to in order to achieve the wicking effect this is accomplished by using braided cop per that is flattened into a band Using solder wick or desoldering braid as it is sometimes called Radio Shack Cat No 64 2090 is easy but there are a few tricks that we ll men tion Take the solder wick and unroll a few inches of it hold it in your left hand with the iron in your right hand Place the wick over the joint and then place the iron onto the back of the wick right above the joint Now let the iron heat the wick which then heats the joint When the solder in the joint becomes moiten it will be wicked up in to the heated braid When this happens the wick will turn silvery you can see this happen Let it stay for a fraction of amp second to wick up as much solder as possible and then remove both wick and iron and presto you re done most of the time that is The technique of wick desoldering is very easy to learn but there are several technical facts that affect the outcome First of all after desoldering a joint you must then cut off that part of the wick that is filled with solder use your nippers to do this solder wick just won t wick after it is filled with solder Always work with a freshly cut edge You can buy solder wick in several dif ferent widths from some electronics
108. ign 4 digital inputs 6 controlled outputs transmitter for BSR R C modules Interfaces with TTL ports or RS 232 A D sampling rate of 28 50 or 1909 samples sec CMOS for low power use can be battery powered 449 standard model Many options available BUSSter Di6R Connecticut Microcoeputer Inc 158 Pocono Rd Brookfield CT 66894 203 354 9395 16 analog inputs of 8 bit resolution 1080 byte buffer for storing readings A D sampling rate 199 sec RS 232 or IEEE 488 available 495 for model described Devices also available for digital input output and analog outputs 495 to 695 MTM1 Software Science PO Box 44232 Cincinnati OH 45244 S13 561 2960 8 analog inputs of B bit resolution 12 digital outputs RS 232 A D sampling speed dependent on baud rate up to 489 sec g 249 circuit board 89 power supply 129 enclosure ONE S Tarus Computer Products Inc 1755 Woodward Dr Ottawa ONT K2C P 613 226 5361 16 analog inputs of 12 bit resolution 16 digital 1 0 channels Has built in amplifier for direct reading of therso couples 2 860 microprocessor control led RS 232 2595 US for standard version 2975 with two analog outputs and 4 counter accumulators 24 run on a Kaypro 4 84 but many other clock cards provide BCD data for date and time values PROCEDURES GETTIME and GETDATE are specific to the Kaypro clock card as written but could be changed to work with m
109. is a very unfortunate choice for 8 beginner for this reason but it s the one to which most of us were first in troduced Not only does BASIC when used without the benefit of training in structured design encourage poin tless jumping from one place to another within the program but it allows new variable names to be invented at any time Misspell a variable somewhere in that maze of instructions and BASIC will go along with it without question even though it means disaster for the program BASIC has singlehandedly brought a whole new meaning to the term debugging Pascal on the other hand requires that variables be defined before they re used and that they be declared accor ding to their intended use There are many reasons for this requirement all of them excellent For example if a string variable is used in BASIC it s stored in memory the first time it is given a value The next time a value is assigned to the same string variable it can t be stored at the same place as its length as well as its contents might change So a different chunk of memory is used and a table is updated to point to the NEW contents of that string variable In a program that sorts a large list of String variables it s likely that a par ticular variable like COMPARES might get thousands of different values stored in it before the sort is finished Each time this happens more memory is used until BASIC finally runs out of va
110. l Borland International Where these terms and others are used in The Computer Journal they are acknowledged to be the property of the respective companies even if not specifically mentioned in each occuren ce The Computer Journal Issue 21 Circuit Designer Continued from page 40 Memory Board Parts List DI D2 D3 1N914 switching diode DIP 1 DIP 2 8 Position dip switch DISP 1 DISP 2 MAN 704 common cathode display IC1 IC2 IC3 74LS373 octal tristate latch IC4 IC5 F9368 hexidecimal decoder IC6 IC7 2114 1K by 4 random access memory R1 R2 R3 1K AW resistor RA 4 7K AW resistor S1 SPST switch S2 SPST momentary switch SOC 1 28 pin I C socket T1 2n3904 silicone transistor Figure 16 Parts list for Memory Board possible The device which Iam referring to is a 2716 EPROM emulator The 2716 EPROM emulator is actually a read write memory with a 2716 EPROM pinout connected to the serial port of any personal computer through a standard UART In addition to programming the CD 1 MPB you will find that the EPROM emulator has many other uses B OVERCOME FORTRAN PASCAL C LIMITATIONS WITH 129 Ver 2 0 For MS FORTRAN Pascal C IBM NO Professional LICENSE and R M FORTRAN FEE SuperSoft FORTRAN A library of over 90 Assembler routines transform FORTRAN Pascal and C language Compilers into the flexible responsive complete languages needed
111. language each time it sees a reference to a procedure or a function it must already know what that operation requires Thus Pascal programs are said to be designed from the top down and written from the bot tom up In the design stage the overall job is split into tasks that need to be done Each task is split further into smaller tasks until finally procedures can be written easily to accomplish those tasks Writing the program is simple then just write the code needed to execute each of the tasks then write the MAIN LOGIC that asks for them to be done as needed Some excellent programmers take a different approach preferring to design the program by writing the main logic itself first Using this method the main logic is written referring to procedures that haven t yet been coded with no thought given to HOW each procedure will be written Once the overall logic is complete the programmer goes back and writes the procedures in detail Because it s so important to writing PORTABLE sections of code ones that can be used in program after program the concept of GLOBAL and LOCAL variables needs to be under stood here GLOBAL variables are defined at the beginning of the entire program and they exist to all parts of the program the main logic and all the procedures This is the familiar ap proach used in languages such as BASIC LOCAL variables are defined at the beginning of each of the in dividual proced
112. m assuming that PrintAt has been saved to disk only the instruction I PrintAt is needed in the source before PrintAt is referenced by name The compiler will stop reading from the source code file that it s working with and read in Print At from the disk then continue with what it was doing Alternately the Turbo editor can be used like WordStar to include such sec tions of code with the source Place the cursor where you d like the procedure to go then type CTRL K R The editor will respond by asking what file name to read from and you ll type PrintAt An extension of PAS is assumed when using the editor to read or write files and will be added automatically unless you add a dot to indicate no extension or add a dot and a different extension Then your file name and extension will be taken literally Upon finding out the name of the file you want to include the Turbo editor will read it in and highlight the text if your terminal is capable of that To get rid of the highlighting CTRL K H works fine again just like WordStar This technique can be used to include a whole library of needed procedures and the user is free to develop several libraries for special purposes When additional procedures are stored together in a single file as a library less disk storage overhead is required and the language can be extended con siderably with only a few keystrokes It s probably obvious by now but the
113. mers who have and use Turbo Pascal It should be obvious that certain escape sequences especially are system dependent and that they will need to be modified a little or maybe a lot to work with a different terminal printer or other peripheral Where this is not obvious I ll point it out In these particular examples specific escape sequences are appropriate for the com puter I use most often a Kaypro 4 849 and the Kaypro Juki 6100 letter quality printer Those who happen to use the same equipment should be able to copy these routines directly Those with other gear should not find it difficult to sub stitute small portions of code that will work for them Many readers will find these exam ples immediately useful but that s not the real reason for sharing them These have been short easy to understand procedures and functions but the same principal can be applied to com plex but routine procedures The IMPORTANT concept is that nearly every command you ve ever wanted in a language can be developed as an ex tension to Turbo Pascal making it one of the most powerful languages that was ever this easy to use Iwant to leave one last recommen dation that will save a lot of time and trouble too although it doesn t have a thing to do with procedures or fun ctions It DOES provide another way to define more keywords Many programs can make use of the terminal capabilities of a computer such as commands
114. mmable microcontroller with 2K RAM and 40 I O lines for less than 200 With INTEGER BASIC as its resident programming language the MC 12 is a versatile controller for a wide range of applications including OEM instrumentation process control research and development and even personal computing It is based on the Zilog 8671 processor and can be upgraded to 16K RAM on the same board or with a 4K or 8K EPROM The MC 1Z is fully self contained easily programmed and comes with a variety of peripherals designed to maximize its utility Included is a clock calendar two fast timer counters 6 interrupts and EPROM receptacle Add cabling and an RS 232 C com patible terminal and you have a com plete applications programmer with BAUD rates from 110 to 19 200 Com plete hardware and software manuals are included and the MC 1Z is available for shipment Contact Fred King at Basicon Inc 11895 NW Cornell Road Portland OR 97229 phone 503 626 1012 Higher Sampling Speed for ADC 1 Remote Measurement has announced an improved version of their ADC 1 Data Acquisition and Control System The analog channel sampling rates have been increased for a choice of 7 to 15 samples per second to a choice of 20 50 or 100 samples per second Application notes are available that provide users with Turbo Pascal routines that can be used to acquire data at the speeds the ADC 1 is now capable of They point out that BASIC programs can be still
115. n and do several before trim ming the wick is necessary Once each pin has been freed turn the board over and using one of the Z80ASM ovv 94 4 99 95 DON T ASK HOW OURS CAN BE SO FAST ASK WHY THEIRS ARE SO SLOW a breath of fresh air Computer Language Feb 85 in two words I d say speed amp flexibility Edward Joyce User s Guide 15 NORMALIZED PERFORMANCE Assemble ZCPR3 to create a HEX file ZAS Mitek Echelon M80 ASM 2500AD ASM 2500AD 37 ZAS TCO as M 1 00 Z80ASM S E 706 22 49 1 00 8Mhz Ram Disk min sec 1 17 3 26 5 25 6 13 2Mhz 8 SSISD Now fully compatible with M80 in Z80 mode with many exten sions Time amp date in listing 16 char externals plus many other features To order or to find out more about our complete family of development tools call or write SLR Systems 1622 N Main St Butler PA 16001 800 833 3061 412 282 0864 Telex 559215 SLR SYS PUN gt C O D Cneck or s mo m Money Order Accepted SHIPPING USA CANADA 3 OTHER AREAS 10 Z80 CP M compatibility required 16 Figure 6 Center of photo shovys three pads attached to heavy heat absorbing traces while in between are three isolated pads which cannot tolerate heat well other pads are normal types larger screwdrivers as a lever pry alternately under each end of the IC If everything goes right the IC will resist a little at first and then sudde
116. n corrupted by having all the spacing removed from it Months later when you need to make a modification you ll be glad you did it the hard way In my experience MTBASIC data acquisition programs are capable of logging analog data nearly as fast as an equivalent Turbo Pascal program provided that use isn t made of the MICROCOMPUTERS AND INTERFACES just to For catalog cali JOHN BELL ENGINEERING INC 400 OXFORD WAY BELMONT CA 94002 415 592 8411 windowing feature which takes time to execute Testing an ADC 1 with nearly identical versions of HISPEED written in MBASIC MTBASIC and Turbo Pascal I got results of 10 88 and 108 samples per second respectively I recommend MTBASIC for applications that can benefit from interrupt driven multitasking capabilities as can many Real World computing applications Mi Jerry Houston has degrees in Business Administration and Data processing and has published numerous articles in the area of Real World computing He is Marketing Director for Remote Measurement Systems Inc of Seattle and teaches computer programming at Griffin College and Seattle Central Com munity College Mail will reach him at Jerry Houston 2633 Eastlake Ave E Suite 206 Seattle WA 98102 32 The Computer Journal Issue 21 Books of interest Design and Application of Small Standarized Components Data Book 757 Published by Stock Drive Products 55 South Denton Ave New Hyde Pa
117. nal recognizes as a special attribute request As easy as reading a procedure from a disk file a text file can be read that contains constant assignments for all these attributes with names that are easily remembered and used in one program after another This file is ac tually the beginning of a Pascal program with all these constants assigned If space is at a premium har dly ever the case with Turbo s virtual memory capability any that are not used for a program can be deleted when the programming is finished It usually doesn t hurt anything to leave them though and they ll be available if you decide later to spruce up the output During the actual coding of the program these attributes can be called upon by Writing them If a particular action is required like turning off the cursor during graphics routines to make a cleaner display it can be han dled separately as in Write CursorOff If an attribute has something to do with a value that s going to be written anyway it can simply preceed it or follow it like any other variable such as Write FlashOn This message flashes FlashOff I use a file called STARTUP PAS to begin nearly every program I write A version of it is shown in Listing 1 Again this file will be of special in terest to Kaypro 84 or later owners but owners of other equipment should appreciate the IDEA On work disks that I use for a special purpose suc
118. nchanged on all the rest If you write for yourself MasterFORTH will protect your investment If you write for others it will expand your marketplace MasterFORTH is a state of the art imple mentation of the Forth computer language Forth is interactive you have immediate TM feedback as you program every step of the way Forth is fast too and you can use its built in macro assembler to make it even EF faster MasterFORTH s relocatable utilities transient definitions and headerless code TM let you pack a lot more program into your memory The resident debugger lets you decompile breakpoint and trace your way through most CP programming problems A string IM package file interface and full screen editor are all standard features MasterFORTH exactly matches the Forth 83 Stan dard dialect described in Mastering Forth by Anderson and Tracy Brady 1984 The standard package in cludes the book and over 100 pages of supplemen tary documentation 47 4 The Computer Journal Issue 20 Back Issues Available Volume 1 Number 1 issue 1 The RS 232 C Serial Interface Part One Telecomputing with the Applej Tran sferring Binary Files Beginner s Column Part One Getting Started Build an Epram Volume 1 Number 2 issue 2 e File Transfer Programs for CPIM The RS 232 C Serial Interface Part Two Build a Hardware Print Spooler Part One Background and Design A Review of Floppy
119. nly lift right off and you ll find little or no trace damage Sometimes there won t be any way to use a screwdriver to get under the IC because of crowded con ditions you ll have to use your imagination to come up with some tool that will do the job some commercial IC pullers made for removing them from sockets can be used in this instan ce although it will be a little awkward The above technique takes only a lit tle more time and effort than the cut and destroy method It can save a valuable IC or at least allow you to test an IC after removal to verify that it was or was not malfunctioning It s worth the effort to practice it but there are no sure things in IC unsoldering sometimes it s a snap and other times it s the IC that snaps To summarize Step 1 Remove as much solder as possible using a de soldering tool 2 Free each pin using a small screwdriver as a probe 3 If step 2 won t work use some solder wick and a hot iron to clear any remaining solder repeat step 2 Single sided boards will usually respond to just the first two steps double sided boards due to the plated thru holes will often require the full treatment Snags and Snaris There are many things that can con spire to defeat your best efforts to un solder a DIP fortunately only one or two problems will rear up at one time If you can identify the problem then you may take steps to overcome it What follows is a rogues gallery of the m
120. ntinued on page 471 The Computer Journal Issue 21 41 14 A 8 nil DISP Rr G e er e ERE GND Ic 4 Figure 15 Memory board schematic t 7 GND 45V a U m a A Lil IF pp mm mur 26056185 j2lsisisieizje Nevv Products The Computer Journal Issue 21 ROMabie MTBASIC Now Available Softaid Inc has released a new ver sion of MTBASIC for OEMs and manufactures of board level computer products The new version MT BASIC ROM can be burned into ROM and will execute from ROM It is only available for Z 80 systems MTBASIC ROM has all of the features of normal MTBASIC except for disk commands since ROM based Systems generally don t have a disk connected Without the disk commands MTBASIC ROM will fit into 24K of ROM A special version is available with disk commands but it requires 30K of ROM Since every vendor s system hasa different configuration and CP M is usually not resident MTBASIC ROM is supplied on disk as REL and LIB files A single assembly language module must be provided by the vendor to configure the I O for the target system There are no royalties for distributing MTBASIC ROM ina board level product MTBASIC ROM is available for 1 100 from Softaid Inc PO Box 2412 Columbia MD 21045 phone 301 792 8096 Linear Optimizer The Acme Computer Company has announced release 2 of their Linear Op timizer program Among the enhan cements in the latest release are
121. of a particular programmer whether he or she is a writer of business report programs or of economics simulations or engineering number crunchers For example when printing business forms like an invoice I wanted a simple command that would establish a print position on the printer such as the standard Turbo Pascal procedure GOTOX Ylh v which places the cursor at a specified horizontal vertical position on the CRT screen A simple procedure can be written to do this ef fectively adding another command to the language Anyone can extend the language with keywords that are familiar from another language if they want Thus a Turbo Pascal instruction could be written such as HTAB 20 VTAB 10 WRITE Hi therel which would do exactly what an old Applesoft programmer would expect it to except in this case with the prin ter So that the runtime library isn t overly large little used commands are not built into Turbo Pascal but left up to the user Exponentiation isn t ac comodated directly by any version of Pascal or C that I know of but can be added easily using the LOG function which is available Thus the MBASIC statement 100 C AAB could be implemented in Turbo Pascal such as C POWER A B once the function has been written and tested Significantly it never has to be written or tested again and can be used wheaever needed Because of the block read and block write features
122. of the Turbo editor it works just like WordStar s CTRL K Rand CTRL K W it s easy to save procedures and functions separately on 8 disk for future use in other programs The 1 include compiler directive will even merge a procedure with a source as it is being compiled making it unnecessary even to read it in with the editor whole personal library of of ten needed procedures and functions can be read into the source code with just a few keystrokes and seldom used ones can be added individually at com pile time The proper construction of procedures and functions and the proper use of local variables with them is an important topic for anyone who s starting out with Turbo Pascal because it helps them to exploit the full power and versatility of this beautiful language Procedures and functions in Pascal share many qualities for con venience I ll refer to both of them as procedures from now on until the time comes to make a distinction Pascal vs Basic For those who are just now being in troduced to Pascal due to the amazing popularity of Turbo I should pause to explain two of the major differences between Pascal and BASIC a language familiar to nearly everyone The first of these differences lies in how variables are used the second in how programs themselves are structured or not Disorganized program design is easy for anyone using languages that do not lend themselves to good structure BASIC
123. oks The disapointment caused by these unrealistic expectations which are due to misleading advertising are the primary reason for the current anti computer backlash It would be like me buying a scalpel today and expecting to able to perform brain surgery tomorrow just because I bought the same tool that a trained surgeon uses My third prediction is that programs will be able to be used by their intended audience without any special computer training What do YOU Predict We are the pioneers of the future The ideas for advancements will come from individuals who are not satisfied with what is available people who can see a better way and figure out some way to accomplish it I challenge you to send your predictions for publication in TCJ M Registered Trademarks Itis easy to get in the habit of using company trademarks as generic terms but these registered trademarks are the property of the respective com panies It is important to acknowledge these trademarks as their property to avoid their losing the rights and the term becoming public property The following frequently used marks are acknowledged and we apologize for any we have overlooked Apple II II IIc IIe Macintosch DOS 3 3 ProDOS Apple Computer Company CP M DDT ASM STAT PIP Digital Research MBASIC Microsoft Wordstar MicroPro Inter national Corp IBM PC XT and AT IBM Corporation Z 80 Zilog MT BASIC Softaid Inc Turbo Pasca
124. ola 680074 1 2 6805 6809 68000 Hitachi 6301 Zilog Z 80 Z 8 Intel 8048 8051 8085 RCA 18027475 DEC LSI Il GI 1650 1670 and others All of the cross assemblers retain the full power of the S C Macro Assembler You can develop programs for burning into EPROMs transfer through a data link or direct execution by some of the plug in co processor cards now on the market Apple Assembly Line Monthly newsletter for assembly language programmers beginner or advanced Increase your skill with the most powerful and important language available for your Apple Packed with techniques handy utility programs commented listings of code from the ROMs DOS and ProDOS reviews of the latest relevant books and hardware and more All back issues since October 1980 available Subscription 18 per year add 3 for first class postage in USA Canada Mexico add 14 postage for other countries S C Software Corporation 2331 Gus Thomasson Suite 125 Dallas Texas 75228 214 324 2050 Professional Apple Software Since 1978 Visa MasterCard American Express COD accepted Apple is a trademark of Apple Computer Inc a deep brown shade from the lacquer materia used to seal them If you can t be sure then proceed as though it is a paper laminate type in other words treat it carefully Wrapup In the Olympic games there is an event called the High Jump It involves one competitor starting from a stan ding position and jumping as high as
125. older the joint that s right re solder it then try to suck it out the solder normally For some reason it works much better this way It it still comes out shiny try wicking the solder out As you work on a recalcitrant joint there s a terrific natural tendency to try too hard to ap ply the iron too long to press too hard remember this and strive to avoid it Let s step back for a moment and take a look at an IC before it s inserted into a board The pins will typically splay out and to insert it they will have to be compressed or bent in Once in position they will splay out again pressing against the side of the hole which on double sided boards will be plated the trace extends thru the hole to the other side No matter how well the solder is removed a small residue will be trapped between the pins and the side of the hole Individually this is a weak connection and in the case of small two lead parts this can be broken by just wiggling the part but with DIP s each leg either 14 16 20 28 on up contributes to the whole and will keep that IC firmly anchored in place To free up these ghost connections will require a simple tool and a moderately difficult procedure Go out and buy a set of cheap jeweler s screwdrivers yes cheap because they won t be used for driving screws in stead they will be employed as probes Feel the ends of each screwdriver and if sharp then round them a little with a file just enough so t
126. olytic capacitor C2 22 mF tantalum capacitor C3 through C9 0 1 mF ceramic disc capacitor D1 1 amp silicon diode D2 D3 1N914 switching diode IC1 8035 CPU IC2 IC3 74LS378 octal tristate latch IC4 IC5 2716 2K x 8 read only memory IC6 74LS280 dual 5 input positive NOR gates IC7 IC8 IC18 74L8138 3 to 8 line decoders 1C9 74LS32 quad 2 input positive OR gates IC10 IC11 2112 random access memories 1C12 74LS86 quad 2 input exclusive or gates IC14 74LS00 quad 2 input positive NAND gates IC185 74LS74 dual D type positive edge triggered flip flops 1C16 74148 8 line to3 line octal priority encoders IC17 T4LS30 8 input positive NAND gate LEDI 0 200 red light emitting diode R1 through R5 1000 ohms R6 4 700 ohms RT 330 ohms 1 S3 SPST switch S2 SPDT momentary switch XTAL 1 MHz to 6 MHz crystal MISC 6 14 pin low profile IC sockets 10 16 pin low profile IC Sockets 1 4 pin low profile IC socket 2 28 pin low profile IC sockets printed circuit board wire alligator clips rubber feet hardware 5 VDC supply 1 amp solder tec Figure 14 Parts list for CD 1 MPB Data Moves Mnemonic MOV A R Move register to A MOV A GR Move data memory to A Increment register Increment data memory Description Bytes Cycles 1 1 Decrement register 1 1 1 1 MOV A data Move immediate to A MOV R A Move A to
127. on and travel to our destination over the same roads using the same maps stopping at the same gas stations without having to be reeducated about how to operate the car There are non standard high per formance vehicles which require special skills but they are for the specialist and not the general public My first prediction is that the unsophisticated user will be able to put their I know that user is singular and their has been plural but I refuse to use he she or his her so I am using their instead program into any one of a large number of computers and run it using the same controls they ll hardly know that they are using a different conputer Floppy disks are slow and easily damaged Hard disks have more storage capacity and are faster but they are not portable and are prone to catastrophic crashs Some form of disk may be suitable for computer centers but the normal user needs something which is non mechanical not easily damaged fast has very large capacity and can be taken to another computer across the street or across the country Optical write once disks sound like a temporary solution because they have large capacity and preserve the data because you do not write over the files but I feel that the mechanical com plexity and potential problems rule them out as a long term Solution My second prediction is that high capacity solid state non volatile memory which does not require batteries will be in general
128. oraatted tiae Get Ti ae Hour Minute Second tritetHour Hinute Second 5 Procedure DrawBox V1 V2 W1 W2 Dyte Begin Write 927 L chr 28 v124 chr 3199192 tche 28 v194 tchr 3140072 8 Write 0927 L tehe 28 v194 chr 31 0202 tchr 32 v294 chr 3140202 3 Write 8027 L tehe 32 v 294 chr 31992692 chre C32 v284 tchr 31 001 2 8 Write 827 L chr C32 ev294 tchr 31949182 echer 28 v194 che 3140182 3 Ends Mis is not code you ll want to type often For drawing outlines on the screen using the Kaypro graphics this draws the four lines needed The four parameters are the beginning and ending vertical positions lines on the screen and the beginning and ending horizontal positions coluans This procedure is written to use values pertaining to cursor positions and to translate those into the graphics positions required by the line drawing escape sequences To draw a box around the entire screen one would use DrawBox 1 24 1 89 Figure 2 screen home the cursor print reverse the ASCII characters above the normal images highlight or even turn off the video display when a key is not pressed for a long time In some cases these terminal attributes make use of some of 0 127 range used for printing and or dinary control characters In other cases such as with the Kaypro these are gained by printing an ESCape The Computer Journal Issue 21 sequence that the termi
129. ort sharp suction at the tip The spring creates a better suction than the bulb type is capable of which makes this tool ideal for working on modern double sided boards Maintaining a spring sucker is much the same as the bulb type in that every so often you ll need to clean out the ac cumulation of solder bits After doing 10 several connections there may be so much solder inside the tip that it will jam up the internal piston to clear this I use a small piece of stiff wire with a tiny L shaped bend on the end poked up into the tip the edge of the wire snares the solder and pulls it out At some point you ll need to disassemble the tool for a complete cleaning Be sure to follow the directions it can be a tricky procedure and due to the spring you could end up with bits of solder flying about if you make a misstep Brush off the internal parts lubricate only as directed and then reassemble the unit One problem with this tool is that the tip will often become distorted due to heat from the solder joints sometimes you can reshape it by careful scraping and cutting but even tually it will need replacing and replacements are available especially for the more expensive of the breed A final word about the spring type sucker try to purchase a good quality model spend a little more than you really want to It s been my experience that the inexpensive variety tend to self destruct after a short period and you re faced with
130. ost common ones By the far the most frequent trouble is caused by residual solder that bonds the IC firmly into position You know this has happened when you try to free the lead or pry the IC off the board There is a fine line between the amount of force needed to remove an IC that is going come off cleanly and one that is stuck in place exceed that line and the IC will break or some traces will come off with it Practice is very helpful to allow you to estimate the force needed but experience is indispensable because boards are different what works on one will fail on others Here are some hints on defeating the residual solder dilemma Always in spect the top of the board look for solder fillets around the IC pins double sided circuit boards with plated through holes are the prime culprits Proper unsoldering techniques should remove these bonds but occasionally one or more will remain Refer back to the procedures outlined above and try to resolder and then unsolder these joints If you find quite a lot of them then an alternative method may help This involves using an unsoldering tool that contains a built in sucker remem ber the missing link place the tool The Computer Journal Issue 21 over the joint let it liquefy the solder then slide it a little to move the IC pin around while releasing the bulb or trigger to suck up the solder The above method also works on cir cuit boards that have small hole diamete
131. p of many procedures some of those will certainly NOT be of use in other programs Using the concept of top down design a single large task is divided into two or more intermediate tasks which are each further broken down into two or more smaller tasks Stringt31 Stringt31 Stringt31 Stringt31 Stringt31 Stringt 31 Stringt31 Stringt 32 Stringt32J Stringt31 Stringt31 Stringt31 Stringt31 Stringt31 StringC31 Stringt31 Char Char Char Char Char 3 3 j 3 3 3 3 3 3 3 j 8 l assigne serial port nusber assigns status port number assigns status mast value port number to set baud rate this value sets baud 96609 Listing 1 Soon these bottom level tasks are small enough and simple enough so that they re easily coded into procedures It is these bottom leveltasksthatare i usually worth saving for future use It makes good sense to set aside a procedure like PrintAt since it would almost certainly be useful in many kin ds of programs A procedure that gathers answers to a series of prompts used in one particular program though wouldn t be very useful elsewhere Examples Some examples of procedures and functions that I ve found useful in many programs are shown in Figure 2 In each case I ve identified the purpose but I won t necessarily point out all the details of Turbo Pascal syntax as this part of the article is intended for program
132. ponse efficient resource utilization link to rest of computing world shop floor to exeautive suite micro to corporate mainframe Call 415 948 3820 for literature Echelon Inc 101FirstStreet Suite 427 LosAltos CA 94022 415 948 3820 hope that you ll still be reading TCJ then My prediction is that in the year 1991 microcomputers will be nothing like the ones we have today and we have no basis on which to forecast what they will be because the technical features they wil use are unknown or at least not well known and would not be feasible with current technology Irealize that predicting that we can not make a prediction is a cop out so TH try to forecast some trends or needs that should be met One of the most ob vious needs is for standardized easy to use hardware operating systems and software Any reasonably intelligent person someone who can use a telephone a stero or drive a car should be able to use a computer 46 with a few minutes introduction And they should be able to use any other computer from a different manufac turer without relearning anything The development of the automobile is a good example of what will have to be done by the computer industry In the beginning there were many companies making dissimilar products but the market forced them to produce cars with standarized controls Today we can get into a Ford Chevy Honda Dodge or Volkswag
133. ram not just the one for which it was originally written To be truly portable procedures and functions should be written using parameters when needed and using local variables These local variables should not be used as global variables within any of the programs An easy way to accomplish that is to use single character variable names for local variables and variable names of more Rever se0n Rever seOft f Hal fIntOn Halfintorf StatusLineOn StatuslineOff Deleteline DeleteToEnd Bell ClearScreen Home SerialPort StatusPort Mask BaudPort BaudRate than one character for global variables This isn t a rule of Turbo Pascal but one I find useful for myself Note for those who are REALLY new to Turbo All identifiers such as variable names procedure names and function names can be up to 127 characters long with each character significant and case is ignored That means that a variable that refers to net profit before taxes can be cailed NetProfitBeforeTaxes if you really want to and a procedure that calculates a standard deviation can be called CalculateStandardDeviation The compiler tokenizes all these names so being descriptive doesn t cost anything at all except maybe a little extra typing Well written a Pascal program can be darn near self documenting and a joy to modify at a later date if that ever becomes necessary Needless to say since Pascal programs are generally made u
134. re MMSFORTM Shipping handling amp tax extra No returns on software Ask your dealer to show you the world of MMSFORTH or request our free brochure MILLER MICROCOMPUTER SERVICES 61 Lake Shore Road Natick MA 01780 617 653 6136 levels Watering and fertilizer ap plication are automated by this system as well as temperature and humidity control T The Environmental Engineering group at Louisiana State University s Civil Engineering Department is developing a remote water quality monitoring and control system for use in soft shell crab mariculture systems The system is based on a Kaypro com puter and an ADC and the objectives of the research include control and op timization of the molting process in blue crabs in totally enclosed aquatic systems Real time data on water quality and system status are collected by conventional laboratory instrumen tation interfaced to the microcomputer through an ADC monitoring pH tem perature dissolved oxygen light and water levels 8 An environmental consulting firm is currently studying the change in air quality resulting from air passage over two Seattle area sanitary landfills Data logging and sampling stations consisting of an ADC a NEC PC 8201 portable computer a wind vane an anemometer and an air sample pump were installed at locatons upwind and downwind of the landfills The NEC is programmed to monitor running averages of wind speed and direction
135. re so you may never en counter these problems Since it makes unsoldering so much more difficult you ll appreciate why we don t en courage its use when assembling a kit Even the cut and destroy method of IC removal is partially ineffective against staked leads The Isolated Pad This is hard to categorize is it an un soldering problem or a board repair problem Certain IC s do not have all their pins connected to the circuit the pad for those pins will have no trace leading away from it it s isolated If WOODEN CLOTHESPINS pl Figure 7 Rough sketch of the scrap wood helping hands described in the article all dimensions and materials can be modified as needed 17 pf on on A A om Y LOCI I I0 II THE AUTONOMOUS ROBOT IS NOW PRICED FOR EVERYONE Buy each subassembly as a kit or factory assembled and create your own GEMINI Robot Or for convenience start with GEMINEX our starter kit and expand to GEMINI later with upgrade kits m LIT asini Either way fco Buy a piece of tomorrow TODAY CALL or WRITE For Our FREE Brochure arctec sustems 9104 Red Branch Road Columbia Maryland 21045 301 730 1237 Telex 87 781 18 you try to unsolder one of these leads you may find that the pad will delaminate it may even be sucked right up into the desoldering tool This is especially likely on single sided boards The best news we have for you is it s not your fault
136. readed Language Part Four Conclusion Interfacing Tips and Troubles Noise Problems Part Three e Multi user Cables and Topology LSTTL Reference Chart Volume 2 Number 9 issue 13 e Controlling the Apple Disk Stepper Motor Intertacing Tips and Troubles Inter facing the Sinclair Computers Part One RPM vs ZCPR A Comparison of Two CP M Enhancements AC Circuit Anaysis on a Micro BASE Part One in a Series on How to Design and Write Your Own Database Understanding System Design CPU Memory and I O Issue Number 14 Hardware Tricks e Controlling the Hayes Micromodem II From Assembly Language e 8 100810 16 Bit RAM Conversion e Time Frequency Domain Analysis BASE Part Two e Interfacing Tips and Troubles Inter facing the Sinclair Computers Part Two issue Number 15 Interfacing the 6522 to the Apple JI and Ne e interfacing Tips and Troubles Building a Poor Man s Logic Analyzer e Controlling the Hayes Micromodem ll From Assembly Language Part Two e The State of the Industry Lowering Power Consumption in 8 Floppy Disk Drives BASE Part Three issue Number 16 Debugging 8087 Code Using the Apple Game Port BASE Part Four Using the S 100 Bus and the 68008 CPU Interfacing Tips and Troubles Build a Jellybean Logic to RS232 Converter issue Number 17 Poor Man s Distributed Processing Base Part Five FAX 64 Facsimile Pictures on a M
137. red in GETDATA as if it were a variable This function first sen ds the ADC 1 its command byte through the serial port port 4 for the Kaypro checks the status port port 6 for the Kaypro and compares the status value to the Mask bit 1 for the Kaypro The status check is repeated until a complete byte has been received then GETDATA is assigned the value read from the serial port Needless to say to use this function with other computers replace the port and mask values used by the Kaypro with those required for your machine Now back to ANALOGIN Model Manufacturer Features Price Model Manufacturer Features Price Model Manufacturer Features Price Model Manufacturer Features Cost The Computer Journal Issue 21 PL 1000 Measurement amp Control Systeam Elexor Associates PO Box 246 Morris Plains NJ 07959 261 299 1615 16 analog inputs of 12 bit resolution plus sign 16 digital inputs 16 digital outputs CMOS for low power use Standalone operation possible with built in BASIC interpretor and 8K RAM Unit can accomodate up to 2 170 boards optional for additional channels RS 232 899 basic system Expansion boards 329 499 Many system options Q 3024 Remote Data Collection System Quasitronics 211 Vandale Drive Houston PA 15342 800 245 4192 2 single ended analog inputs 4 digital outputs A D resolution 1 in 56409 or 1 in 20000 using BCD digits s
138. register MOV R A Move A to data memory MOV A data Move immediate to register MOV R data Move immediate to data memory MOV A PSW Move PSW to A MOV PSW A Move A to PSW XCH A R Exchange A and register XCH A R Exchange A and data memory XCHO A GR Exchange nibble of A and register MOVX A QR Move external data AM memory to A positives can also be supplied for a MOOR A umemoy reasonable charge on request The silk e ee a screen which outlines each functional MOYFSA More te A trom pag 3 section of the CD 1 MPB is especially useful for instructional purposes and adds to the overall appearance of the board Control Conclusion As mentioned earlier Mnemonic there may be times when you will want S val rio to write larger programs to be DIS DENN ATH executed by the CD 1 MPB Further SEL RBO Select register bank 0 more you may want to purchase an Rue pr EEG 8035 assembler so that you can write SEL MB Select memory bank 1 the code in assembly instead of machine language In the next issue of The Computer Journal I will present a device which will make these things Timer Counter Mnemonic Deecription MOV A T Read timer counter MOV T A Load timer counter STRTT Start timer STAT CNT Start timer STOP TCNT Stop timer counter EN TCNTI Enable timer counter interrupt DIS TENTI Disabie timer counter interrupt ENTO CLK Enabie clock output on TO No operation Select idle Operation Co
139. riable storage space and has to stop to GARBAGE COLLECT the usual term for reclaiming the space used by all the PREVIOUS CONTENTS ofa string This process can actually stop the execution of a program for minutes at a time depending on the computer Pascal on the other hand assigns ONE AND ONLY ONE area of memory to store the contents of any variable including a string It does this by requiring that the user declare not only the NAME ofa string but also its maximum LENGTH Since the same storage location is re used each time a new value is assigned there s no such thing as GARBAGE COLLECTION in Pascal Since all variables are declared before they re used it is a simple mat ter for the Pascal compiler to call errors to the programmer s attention If a variable name is misspelled part way The Computer Journal Issue 21 thorugh a program the compiler will in effect say What s this when it sees the error Turbo Pascal sets aside the amounts of memory shown in Figure 1 for the particular types of variables and that same space is ALWAYS used to con tain the current contents of that variable Using the keyword ABSOLUTE a variable can be assigned a memory location of the programmer s choice or Turbo can be allowed to keep them ina data storage section Like variables procedures and fun ctions must be declared before they are used When the compiler reads through the list of source code to convert it to machine
140. ription inquiries to The Com puter Journal 190 Sullivan Crossroad Columbia Falis MT 59912 Editor s Page Mid Level Languages Being Developed When the first hobbyists built their microcomputers they had to code their programs directly in machine language but they soon wrote assemblers which enabled them to use easier to remem ber mnemonics for their source code Language development continued and BASIC became the familiar language for the new micro owner Today there is an almost overwhelming assortment of languages to choose from with something for every purpose and it seems that there should be no reason to work on language development but there are those who are not satisfied with what exists and who feel the need to build on the foundation which has been established Telling a sofware hacker not to waste his time on language development because everything has already been done is like telling an author not to write another novel because everthing has already been written about or telling an artist not to bother painting another picture because every kind of picture has already been painted While it IS true that there is a suitable language for almost every purpose it is also true that there are some applications for which there is not an optimum language As I have stated before I contend that we should all be comfortable working in at least two or three languages and familiar with two or three more so th
141. rk NY 11040 Distributed by Educational Products PO Box 606 Mineola NY 11501 784 pages 54 2 x 7 2 softbound 7 95 One of the reasons I became so in terested in computers is that they enable me to control mechanical devices such as lathes robots and other motion producing devices I have a long list of mechanical projects to work on and I have most of the com puter programming and interfacing in formation I need but I have had dif ficulty locating application information on the small gears shafts bearings motors timing belts etc needed for assembly We live in a rural area and the saying is If it doesn t fit on a steer or a sawmill you can t get it I can get information on two inch diameter shaf ts and bearings but if I ask about 1 16 shafts they look at me like I m nuts I probably am or I wouldn t be messing with computers but that s besides the point I was very happy to locate this Data Book and they also have Master Catalog 757 Handbook of Small Stan dardized Components in which they list parts for sale It is difficult to review this Handbook because it is a collection of text charts and specifications on a wide variety of subjects and I can t list everything it covers I ll briefly describe the various sections and comment on the parts I find escecially interesting Section D1 Designers Data Part A Mathematical formulas and tables in cluding energy inertia torque power and work
142. rogram is saved to EPROM it is tagged with an iden tifying number and stored only in the amount of EPROM required to fit the program Additional application programs can be stored to the same EPROM and recalled for execution by requesting a particular ROM number or designated as an autostart program Since the BASIC 52 is bus oriented it supports Micromint s Term mite ST smart terminal board BCC14 memory expansion board BCC33 I O expansion board BCC40 AC DC I O board BCC13 A D converter board and BCC08 serial I O expansion board The BASIC 62 Computer Controller with 8K bytes of RAM is available for 239 For orders call 1 800 635 3355 For technical information or to request a data sheet call 1 203 871 6170 Continued on page 50 Extends the lle to 128K RAM Adds 80 column video display Enhances spreadsheet and word processor rine Allows double high resolution raphics Eb instolls in slot 3 of the Apple He Comes with full Soumen MICROPORT 32 arbitration circuit interrupt routing WEM tions New low price EXTEND 50 switches and more Excellent choice for monitoring and control applico Micro Systems Research 4099 Maxanne Drive Kennesaw Georgia 30144 Reliably extends all 50 signals at inter nal slots to a 50 pin DIP One side plugs into an Apple slot the other pl into ony breodboord protoboon Now you can easily wire on interface card circuit without t
143. rooms in which apples are stored Temperature light and relative humidity are carefully con trolled so that the fruit will become dormant but not die and it can be brought to market months later in just picked condition 12 Two professors in the Depar tment of Urban Planning at the Univer sity of Washington are using an ADC with an IBM PC to study the effects of lighting glare and solar radiation on personal comfort and energy management for new building design and construction Subjects are placed in a room with a desk and lamp and asked to determine what level of light they find to be most comfortable to work with The subject controls a hand held device which through the ADC is used to brighten and dim the level of solar light emitted by an artificial window in relationship to the level of internal light while maintaining a total illumination constant 13 A sophisticated home control system has been developed by a Seattle resident using an ADC and a Macin tosh The system monitors and graphs energy use temperatures basement moisture and a variety of security sen sors When a possible security in trusion is detected lights are turned on progressively closer to the source of the alarm simulating someone ap proaching and turning on lights If ef forts to enter continue a conventional alarm is sounded Home temperatures are controlled to different setpoints ac cording to time of day and occupancy
144. rs soldered on both sides for the ICs Care must be taken to insure that cold solder connections are avoided One faulty connection on a single board computer could cause many hours of troubleshooting misery before the problem is located parts placement layout is provided in Figure 13 to aid in the construction and assembly of the CD 1 MPB and a complete parts list is provided in Figure 14 f Figure 10 is a photograph of the completed CD 1 MPB Full size positive prints of a silk screen outline and the front and back foil patterns are available for 1 00 postage Film The Computer Journal Issue 21 e RI LEDI i Socket E Dr le Socket D L Socket G IC 4 Tages pe am Socket B Socket F Socket A CC 8 1 ie 14 Des Gje ER XTAL T 2 ede E e 16 Figure 13 Parts placement received my moneys worth with just one issue 4 Trenbick alvays stop ta read CTM even though most other magazines l receive and write for only get cursory examination Fred Blechman K6UGT USUAL ERI SAT cp 15 00 for 1 year Mexico Canada Foreign U S funds only Permanent U S Subscription Sample Copy CHET LAMBERT W4WDR 1704 Sam Drive e Birmingham AL 35235 205 854 0271 FREE SOFTWARE RENT FROM THE PUBLIC DOMAIN User Group Software Isn t copyrighted so there are no fees to pay 1000 s of CP M and IBM software programs in CO
145. rs where the standard procedure is not adequate Once ina great while you may encounter boards with such tiny hole diameters that nothing may work At this stage we should point out that whenever something is soldered together there is the implied assumption that it will never need to be unsoldered some designs can make it very hard indeed to safely unsolder an IC If you absolutely must accomplish such a task there is a tool that may do it for you It s an ac cessory for certain soldering irons that is shaped so that it contacts all the pins of an IC at one time It s not inexpen sive and you need one for each IC size and above the 16 pin size it becomes rather impractical therefore we ll only note its existence without a detailed examination of this tool type There exists yet another reason why certain IC pins may contain residual solder Any pin that is connected to a large trace such as a ground or power pin will prove difficult to unsolder Using a larger tip on the iron will often help as well as using solder wick Sometimes these pins may resist all ef fort to remove the solder but there is usually only one or two per IC These are easy to deal with if you have three hands Seriously the third hand is really any sort of holder for the board that lets you reach around to the component side with one hand and apply the soldering iron with the other hand The scrap wood holder described earlier or a commercial product work
146. rst seven tasks are designed to read the analog channels of the ADC 1 system and would certainly have to be modified to work with a dif ferent interface They are so similar except for variables that indicate the channel that was read and cursor positioning that I ll explain only the first task then go on to tasks 8 and 9 which read the clock card and write to disk Task 0 zero is the main logic of the program and it actually includes all the code up to line 545 the STOP command Line 251 uses the familiar OUT statement to send a value of 14 to port 0 setting the Kaypro serial port to a baud rate of 9600 Other computers ac complish this with different port num bers and values or with an OPEN statement 28 The ERASE statement in line 252 clears the screen Since VINDOV 0 used throughout the program so that the CURSOR positioning statement will work includes the entire screen the WCLEAR statements as in 260 also clear the whole screen In other cases they could be used to clear just a single window while leaving the rest of the screen alone Line 253 selects WINDOW 0 for use until another WSELECT statement is given Line 255 establishes that WIN DOW 0 will exist from screen lines 0 to 23 and from screen columns 0 to 78 WFRAME defines the characters to be used to outline the screen the first character used for the horizontal lines top and bottom and the second used for the vertical lines sides After the
147. s they want the IC s generally we ll want to preserve the board and perhaps the IC By the way resistors capacitors etc have leads IC s have pins or sometimes legs but all three terms are used inter changeably If you don t want to save the IC then the best approach is to cut it off the board Clip each leg as close to the IC body as possible until the body falls away Next get a small spring loaded heatsink forceps or tweezers with a rubber band to clamp it shut invert the board and clip this tool onto a pin so that gravity aided by the tool s weight is acting to pull out the pin Heat it with an iron being sure to press the iron evenly against both trace and pin but don t wedge the pin use a gentle touch You want to be sure to contact both so that on double sided boards the heat will be transfered to the trace on top Once the solder liquefies the pin should fall out Repeat for each pin There is a variation that requires a little more dexterity and doesn t always work smoothly In this method you omit the heat sink or forceps and just heat the pin until the solder liquefies then tap the board against the edge of your workbench and it should pop out Alternately some people blow the pin out when the solder liquefies The Computer Journal Issue 21 this requires dexterity and practice and as a hot soldering iron is involved can be hazaradous Occasionally the pin won t come out because it has wedged don t
148. s a new user will BSO EPRINTS RO PRINT VALUE READ need to look out for S6 K 1 SENSOR e 1 DATA TO DIBK FLAG T 865 INTON INTERRUPTS BACK ON Praises to its inventor for providing 878 EXIT END OF TASK 1 some Pascal like features in MTBASIC ate Variables are defined before use as in 980 TASK 2 DEFINE BEGINNING OF TASK 2 li 00 146 M l i li f 918 IF CHANNEL 2 THEN 1138 SKIP IF CHANNEL NOT SELECTED ines 1 Multi line functions are 915 INTOFF INTERRUPTS OFF Sidekick for CP M Write Hand Man Desk Accessories for CP M NEW Now with automatic screen refresh Suspend CP M applications such as WordStar dBase and SuperCalc with a single keystroke and look up phone numbers edit a notepad make appointments view files and directories communicate with other computers and do simple arithmetic Return to undisturbed application All made possible by Write Hand Man Ready to run after a simple terminal configuration No installation required Don t be put down by 16 bit computer owners Now any CP M 2 2 machine can have the power of Sidekick Bonus User extendable Add your own applications 49 95 plus tax California residents shipping included Volume and dealer discounts Available on IBM 8 inch and Northstar 5 inch disks Other 5 inch formats available with a 5 00 handling charge CP M 2 2 required CP M 3 not supported COD or checks ok no credit cards Poor Person Software 3
149. socket and disconnects the address bus multiplexer outputs of the CPU board from the memory ICs IC6 and IC7 The address and data buses are now free for use by the memory board 3 The address and data lines to the memory ICs are connected to a set of DIP switches via IC1 IC2 and IC3 74LS373 s When the run examine switch S1 is in the examine position closed a ground is applied to pin 1 of IC1 and IC2 thus connecting one side of the ad dress DIP switches to the address inputs of the memory ICs The memory ICs are enabled via a ground applied by switch S1 through diode D2 The data DIP switches remain disconnected from the memory ICs until the deposit switch S2 is depressed and logic states are applied to the address and data bits via the DIP switches When the switches are open the lines are floating and the memory ICs see a logic 1 To apply a logic 0 The Computer Journal Issue 21 D BLE Figure 11 Circuit Designer 1 P MPB Block Diagram gj 4 Y 2 Hop ff NeT An a 2 o y d SS Advance Li 7 SS Selec AI we z A 1 N Z t t 5774 LLL IPL LAT LEN Z AP ILLL A 2 SILILA 4 4 8 170 Z f KVIZIZIZA U v vice f sever K intera CODES Z VA SS PRIORITY v y f 7 Z 4 us u INTERRUPT I 2 2 7 t 2 g ALE ol INT ACK gt J 4 VC LAL LLL Ah VIZ LH LLL ULL wz27rz772772727272z2274 P2 P2 e Ao A7 7 Address Bus Ag Aj A 7 J A f A PA 7 f 2 7 VA pa 4 VA Z Pa j f h f 2 G Ld f 4 f f
150. t EPROM which will directly replace the memory board The 2716 EPROM is non volatile memory which means that when power is removed it will retain its program This enables the CD 1 microprocessor board to be utilized as a dedicated monitor and or control device The CD 1 microprocessor board has sockets to accommodate two 2716 s so that frequently used subroutines could be written into a 2716 and placed in the higher 2K byte memory socket With the CD 1 memory board plugged into the lower 2K byte memory socket dynamic programs can be written with the ability to call subroutines from the 2716 EPROM on the microprocessor 6Mhz HD648180 Z80 upward compatible 51 byte on board 256K installed 384K RAM S LAN ZENET port 800K baud CSMA CD type upto 500 meters HDLC Floppy 3 5 5 and 8 inch dis EA d s track automatic de K e Hard disk SCSLinti from disk back up calendar Full featu 280 4mhz 128K Byte iba Mountain Side Computer and ZENET are trademark of Southern Pacific Limited 9 Size 10 X 6 inch 4 layered Distributors England Quanta systems 001 253 8423 Manufacturer and international distributer SOUTHERN PACIFIC LIMITED and 640 X 200 K video RAM characte ey pde oye bits VO 7 8 bit 2e rs Turbo Dos MP M multiuser banked CP M plus single user e Size 10 X 6 inch 4 layered Assembled and tested e BIOS source code available OS CP
151. t article the design of the CD 1 MPB an 8035 based single board computer was presented and its operation was explained This month I will mention a few applications for which I have personally used the CD 1 MPB and we will present a simple read write memory circuit which plugs into the CD 1 MPB program memory socket and allows the user to enter pro grams in machine language The CD 1 MPB was originally created because of the need for a sim ple general purpose single board com puter to be used as an intelligent con trol unit in several projects which were under construction Among these projects were an automatic telephone number recording system a CO gas monitoring instrument and a classroom microprocessor trainer The CD 1 MPB successfully served as the control unit for all of these projects with changes only in the software from project to project Programming the CD 1 MPB The Instruction Set As in any microprocessor control system operations are controlled via program instructions The 8035 has an instruc tion set which consists of 90 commands The 8035 literature is out of print but specifications on the 80C35 which has the same instruction set are available from Intel by calling 1 800 538 1876 or 1 800 672 1833 in California and requesting the 80C48 80C35 Specifications 210943 001 The instruc tion set for the 80048 80C35 80C 49 and 80C39 is shown in Table 4 The Interface Sockets The CD 1 MP
152. t functions and you have a faster Z80 machine The MMU memory management unit part of the HD64180 is pretty standard and will make it possible to program any 4K segment of the 512K space into the 64K operating system space This is done by loading registers with offset values with the necessary register selection based on the logical upper four bits 12 thru 15 The lower 12 bits are added with the MMU registers 7 bits and the upper logical 4 bits to create the physical address The preliminary data sheets didn t have the actual code needed to do this so when I get the big manual I will cover more of the features in greater detail then The Main drawback of the unit is the 64 pin socket There will most likely be a shortage of these at the start so using the chip will require headers at first A project that I will undertake when more information is available and the units are for sale here in the U S ata reasonable price will be an adaptor for Z80 machines to make use of the new features such as extended memory ad dressing I am thinking of some kind of paddle board that will have a Z80 header a socket for the HD64180 jum pers for extended memory or sockets for more memory and serial buffers to make use of the extra serial ports This shouldn t require more than five or six components not including memory The biggest problem will be getting the HD64180 and enough information to make it work Forth ROM
153. t into memory A 120 tunction library written in both C and assembly language with full Source code Plus A thorough easy to read 181 page user s manual complete with tutorials hints error messages and an easy to use index it s the perfect manual for the beginner and the seasoned professional An attractive selection of sample programs including MODEM compatible telecommunications CPIM system utilities games and more A nationwide BDS C User s Group 10 membership fee application included with package that offers a newsietter BDS C updates and access to public domain C utilities Reviewers everywhere have praised BDS C for its elegant operation and optimal use of CPIM resources Above all BDS C has been hailed for it s remarkable Speed I recommend both the language and the implementation by BDS very highly Tim Pugh Jr in nfoworld Performance Excellent Documentation Excellent Ease of Use Excellent InfoWorld Software Report Card a superior buy Van Court Hare in LifelinesThe Software Magazine BYTE Magazine placed BDS C ahead of all other 8080 Z80 C compilers tested for fastest object code execution with all available speed up options in use In addition BDS C s speed of compilation was almost twice as fast as its closet competitor benchmark for this test was the Sieve of Eratosthenes Don t waste another minute on a slow language processor Order
154. ter D A outputs can be used to control the speed of motors operate chart recor ders or provide a variable voltage for other special purposes Resolution has to do with the ac curacy and sensitivity of the analog in puts and ultimately with the cost of the equipment and the speed at which it can operate Since the resulting digital value is sent to the computer as a collection of bits that are either ON or OFF a convenient and common way to refer to the resolution of an ADC is in terms of the number of bits used ADCs are commonly available that provide 8 bit or 12 bit resolution and not so commonly with 16 bit or higher The size of each increment of resolution has to do with the overall range that can be read by the inputs represented as a voltage and the num ber of bits of resolution Since each bit can represent only one of 2 conditions ON or OFF 8 bit resolution provides 2 raised to the 8th power or 256 in crements 12 bit resolution offers 2 to the 12th or 4096 increments If the ADC is also capable of determining polarity then it can differentiate that number of increments to either side of zero doubling range with the same resolution To put resolution into perspective consider that you might want to monitor and control the temperature of a heat treating furnace Your sensor might be one that operates over a range of 0 to 2000 F and you probably would have the ADC input well mat ched to the sensor so
155. ter available to owners Makes your Apple into a NEW sechine l 2 3 4 5 6 7 8 9 MAIL CHECK TO JOHN BLANKENSHIP P O BOX 47934 ATLANTA GA 30362 FOR TRS 80 MODELS 1 344 IBM PC XT AND COMPAQ The MMSFORTH System Compare e The speed compactness and extensibility of the MMSFORTH total software environment optimized for the popular IBM PC and TRS 80 Models 1 3 and 4 An integrated system of sophisticated application programs word processing database management communications general ledger and more all with powerful capabilities sur prising speed and ease of use With source code for custom modifications by you or MMS The famous MMS support including detailed manuals and examples telephone tips additional programs and inexpensive program updates User Groups worldwide the MMSFORTH Newsletter Forth related books work shops and professional consulting A World of Difference The total software environment for IBM PC TRS 80 Model 1 3 4 and close friends e Personal License required MMSFORTH System Disk IBM PC 249 95 MMSFORTH System Disk TRS 80 1 304 129 95 Personal License optional modules FORTHCOM communicaticns module 39 FORTHWRITE word processor Corporate Site License Extensions eSome recommended Forth books UNDERSTANDING FORTH overview STARTING FORTH programming FORTH techni technique BEGINNING FORTH
156. that clear the The Computer Journal Issue 21 Procedure HTAB X Byte Begin Write 1st 827 811 chr 0 Endi Perfores a printer horizontal tab to the position given in X Procedure VTAB X Byte in Writet1st 9027 49 chr 0 3 Perforas a printer vertical tab to the line given in X Function ACD X Byte Bytes Begin ACD s5 X Div 16 9 19 X 16 X Div 1620028 Converts BCD binary coded decimal values to ASCII decimal values Used in the procedures below that read fron a clock Ocalendar card as the usual output froe these clocks is in BCD Procedure GetDate Y M D Byte Begin Port 34 153 wake up Kaypro clock card Port 321 9 ask for year Y ia ACDIPortI361 8 get year Portt32 73 ask for month M ACD Port 361 8 get eonth Portt32 64 ask for day D ACD Portt361 5 get day Endi Gets the date from the Kaypro 4 64 clock card In a program code such as the following sight be used to write a foreatted date GetDate Year Month Day Write Ponth Day 7 Year Procedure GetTiae H M S Byte s Begin Portt343 153 wake up Kaypro clock card Portt321 43 ask for hour Y is AcDIPort i 3482 8 get hour Port 322 33 ask far minute M 9 ACD Port 34I 3 qet minute Portt321 9 21 ask for second D ACD Portt 35225 get second End Sets the tiae from the Kaypro 4 84 clock card In a progras code such as the following aight be used to write a f
157. the low byte One final check is made to determine whether the sign flag was cleared if HighByte AND 16 0 then the value is a negative one and the ap propriate sign is added The procedure to calculate the square of the sample mean is used with the following procedure that calculates the sample standard deviation All the analog readings that have been taken were stored in the array Buf fer 1 10000 For the number of readings that were requested these elements are summed then divided by the number of readings to provide the arithmetic mean Then this mean is squared The standard deviation procedure is straightforward It squares each in dividual reading sums the squares and uses a very standard statistical formula to determine the standard deviation of the entire sample The program main logic should be easy to follow as the variables procedure names and function names are self describing Basically the program asks the user how many sam ples to read checks the time reads the samples and stores them to the Buffer array then checks the time once more The number of seconds required to do the reading is divided by the number of readings made to determine how many samples per second could be read The user can decide to display all of the samples to the screen for a visual check or only a few of them Pressing RETURN will display them all The number of them that were displayed to the screen will be used to calc
158. to decipher if written by someone else There isn t and never will be a perfect language which is optimum for every use A program properly written ina structured high level language such as C or Turbo Pascal takes less time to write and is much easier to maintain or modify if your requirements change but some sections may be too slow for time critical real world control ap plications or computer bound portions Some language implementations also have a large run time code which results in large files for even small programs I really like assembly language for the high speed routines and for initiating system port drivers but I don t like the time and effort in volved in non critical areas such as screen messages and menus The experts say that you should fully define the objectives and design your program before writing any code in stead of hacking away at it and making Continued on page 44 Extending Turbo Pascal Use Procedures and Functions to Develop Your Own Version by Jerry Houston The Computer Journal Issue 21 po A LUE A SO a I TO SS I NI I EEN PALS B ecause Turbo Pascal s procedures and functions allow the use of local variables that don t conflict with other parts of the program and because parameters can be passed to them it is really easy to define new keywords in effect That means that a version of Turbo Pascal can be developed that meets the individual and personal needs
159. try to tap or blow it out any more as you ll risk damaging the board by repeated attempts instead use the first method described above Suppose that you want to get the IC out intact The first step is to remove the solder from each pin exactly as you would for any other component Use a solder sucker bulb or spring type and as in the technique above be sure that the heat transfers to the opposite side by butting the iron against both pin and trace Irregardless of whether you re trying to save the IC or not be careful not to overheat each joint Overheating can damage the printed circuit traces especially the small ones that cluster near IC s Hold the iron no more than four possibly five seconds tops To measure time use a counting technique such as saying One Mississippi Two Mississippi etc It takes almost exactly a second to say each iteration and any multi syllabic state name will do such as One Massachusetts etc Just don t alter nate back and forth as that will confuse both time and geography a sure fire route to the Twilight Zone Allow a little time between the pins so that the IC can cool internally Once all the pins have been cleaned carefully inspect them a magnifying glass is helpful Look for a dark half moon in each hole this indicates that most of the solder has been sucked out If the hole still looks shiny then solder probably remains in it To fix this don t try to suck it out instead re s
160. tter to use a solder sucker and remove the wire in tact After using the solder sucker you will find two possible conditions either the wire will pull right out with gentle tugging or it won t The reason it may not is that enough solder is left in the connection to hold the wire from releasing More art now is required you may be able to free the wire by using some solder wick and wicking out the remaining solder typically this should only be necessary if you really didn t do a good initial job of sucking out the solder perhaps you didn t use an iron sized to the joint maybe you used a bulb type sucker and not enough vacuum was developed maybe some solder remains on the opposite side of the board Another possiblity is that wire is a very tight fit to the hole and even a small trace of solder will keep it held fast In this case what you may need to do is to fix the board in a holder grab the wire on the opposite side with one hand far enough away so you won t be burned and apply the iron while you pull gently as the iron heats the bit of solder it should lose its grip on the The Computer Journal Issue 21 Figure 5 Jeweler s screwdrivers used to pry up an unsoldered DIP On the left side a resistor acts as fulerum for the lever on the right another screwdriver at an angle is used with the levered blade threaded between some transistors wire Parts with two or three leads are very common To unsolder these just
161. ud rates 300 1 2k 2 4k 4 8k 9 6k and 19 2k baud Data format for program ming 15 absolute code n e it will program exactly what it is sent starting at EPROM address 0 Other standard downloading formats are easily converted to absolute object code The APROTEK 1000 is truly universal It comes standard at 117 VAC 50 60 HZ and may be internally jumpered for 220 240 VAC 50 60 AZ FCC verification CLASS B has been obtained for the APROTEK 1000 APROTEK 1000 is covered by a 1 year parts and labor warranty FINALLY A Simple inexpensive Solution To Erasing EPROMS APROTEK 200 EPROM ERASER APROTEK 300 oniy 60 00 PROTEK il R This eraser is identical to A and switch ON In about 10 metes 200 but has a Dustin timer so that the you switch OFF and are ready to ultraviolet lamp automatically turns off in reprogram 10 minutes 2hminating any risk of overex APROTEK 200 only 45 00 posure damage to vour EPROMS EK 200 only o APROTEK 300 oniy 60 00 APROPOS TECHNOLOGY 1071 A Avenida Acaso Camarilto CA 93010 CALL OUR TOLL FREE ORDER LINES TODAY 1 800 962 5800 USA or 1 800 962 3800 CALIFORNIA TECHNICAL INFORMATION 1 1805 482 3604 Add Shipping Per item 3 00 Cont U S 6 00 CAN Mexico HI AK UPS Blue The Computer Journal Issue 21 928 WSELECT 8 938 CURSOR 11 3 946 PRINT gt gt READING gt gt 5 958 QUT 4 1 IF BANDIINPIS 1 THEN 968 t 976 CHARIN INP 4 986 OUT 4 161 IF BAND
162. uires good technique Instead use solder wick just place it over the bridge heat the wick with the iron and bingo the bridge disappears into the wick This works so Figure 3 A small screwdriver employed to fracture the bond between DIP lead and plated thru hole by firm inward pressure 12 well that sometimes you will have go back and resoider the joint because too much solder went into the wick but it still beats the old soldering iron method I would be sure to include some solder wick in my tool kit if for no other use than removing solder bridges One final note as in all soldering and unsoldering never leave a heated solder wick on a connection too long if the process doesn t work in a few seconds then there is something else wrong and leaving the iron in place longer will only damage the circuit board or the parts you re working on Helping Hands One basic rule if you re trying to un solder parts from a circuit board that board must be firmly fixed in place if you re unsoldering a wire from a lug then the lug must be firmly fixed It is virtually impossible to hold something down while trying to unsolder from it and equally impossible to unsolder moving parts so you have to employ some type of holder to fix things in place One tool is Radio Shack s Helping Hands Cat No 64 2093 you can also use small vises such as those sold by Radio Shack All these bits and pieces can start to add up especially if
163. ulate the standard deviation Another RETURN N 337 25 Program 1 LOGGER BAS IS amp PROGRAM TO READ UP TO 7 CHANNELS FROM AN ADC 1 DATA ACQUISITION AND CONTROL SYSTEM AND LOS DATA TO A DISK FILE THIS SOURCE CODE MUST BE COMPILED WITH THE MTBASIC COMPILER AVAILABLE FROM SOFTAID INC JERRY HOUSTON REMOTE MEASUREMENT SYSTEMS INC 286 328 2255 INTEGER I J K R C INTEGER YEAR MONTH DAY HOUR MINUTE SECOND INTEGER HBYTE HMASK LBYTE CHARIN RESULT INTEGER TIKSI TIKS2 TIKSI TIKSA TKS 7 INTEGER TIKSS TIKS6 TIKS7 INTEGER CHANNEL 7 INTEGER CONVERT X INTEGER SENSOR STRING FNAMES 14 LABELS 28 7 STRING As STRING CONS 3 COFFSCI UTILITY COUNTERS DATE AND TIME VALUES ANALOG READ VALUES TIMING VALUES MORE TIMING VALUES FLAG CHANNEL USED FUNCTION NAMES DECLARED LAST CHANNEL READ FILENAME CHANNEL LABELS Y N INPUT FROM CONSOLE CURSOR ON OFF KAYPRO 9 9 9 v ov 9 we THIS FUNCTION CONVERTS BCD NUMBERS FROM CLOCK CARD TO ASCII DECIMAL REPRESENTATION FOR USE BY SCREEN AND FILE DEF CONVERT X CONVERT X 16 18 X lig X 160 0 FNEND s FOR I 1 TO 7 CHANNEL I NEXT I INITIALIZE CHANNEL FLAGS E THESE ASSIGNMENTS CREATE TWO STRINGS THAT WILL TURN THE R KAYPRO CURSOR ON OR OFF PROVIDING CLEARER DISPLAY ON THE CRT CONS CONCATS CHRS 27 B CONS CONCATS CONS 4 COFFSECONCAT 8 CHR8 27 C COFFS CONCATS COFFS 4 E MODULE
164. ures instead and have meaning only to that procedure and to other procedures that it calls This con cept is called SCOPE That means that I can define a String USE Takes on value of True or False only Often used as a flag to indicate whether a condition exists Integer type variable can contain whole nuabers from to 255 Most efficient for counters where the number of iterations won t exceed this range Can contain whole numbers from 32768 to 32767 Faster numeric operations than Real Nuabers and rwquire only 1 3 their storage space Ideal choice for numerics that won t take on any fractional values Often called Floating Point variables as they can express a numeric value with a decimal point in it Can store values troe 1E 38 to 1E 38 Turbo Reals contain up to 11 significant digits Short version of a string variable Can take on any value of a character in the ASCII character set that is with an ordinal value from to 255 As usually thought of in other languages like BASIC Strings can contain up to 255 characters They are stored in an area of eemory that contains one byte for the length then one byte for each character the string is defined to hold Figure 1 variable called COUNT in several procedures and use it as a counter in each of them and never have to worry about whether one part of the program will change the value of a variable used in another part Each version o
165. used and even the BASIC programs will show some increase in speed with the new version The ADC 1 is compatible with any computer with an RS 232 C serial inter face The system provides sixteen analog input channels with a resolution of 12 bits plus sign 11 bits at high speed four digital inputs six hardwire controlled outputs and the ability to operate BSR type AC line carrier remote control modules The ADC 1 allows the user to concentrate on the design of the project and program free from the details of electronic inter facing The host computer or modem sends commands to the ADC 1 in a single 8 bit byte through a serial port For each byte received the ADC 1 returns an 8 bit byte that contains status and measurement data The com munications interface supports stan dard RS 232 C as well as the TTL levels used by Commodore and Atari serial ports Baud rates are selectable from 300 to 9600 bps Interconnection in structions and programming examples for most popular microcomputers are included in the owner s manual Sensitivity of the analog inputs is 0 1 mV ofer a range of 0 4 V modifiable to 4 0 V The A D inputs are user configurable for operation at 20 50 of 100 samples per second An optional in strumentation amplifier provides sen sitivity at microvolt levels for use with thermocouples The four digital inputs may be used to monitor or count on off signals at up to 400 Hz while the six controlled outp
166. utput disable active high RESET CPU reset active lo RD external data memory read pulse WR external data memory write pulse TO a test input which may be sampled by a conditional jump instruction The internal CPU clock signal can be output via TO T1 A test input which can be sampled by a jump on condition instruction T1 can also be used to input a signal to counter timer logic when it is serving as an event counter M D External memory disable OUT 0 through 7 output device code pulses IN 0 through 7 input device code pulses board The memory circuit explained above is adequate for entering small programs for system checkout or for gaining an understanding of how the CD 1 MPB operates on its most basic level But if longer programs are to be executed on the CD 1 MPB some other method of entering code will be needed Inthe next issue of The Computer Journal a more effective way of en tering program instructions into the 8035 program memory space will be discussed Figure 12 Interface sockets Construction of CD 1 MPB Double sided circuit boards have presented a problem to hobbyists in the past because of the need for plated through holes The CD 1 utilizes a double sided board but to eliminate the need for plated through holes I have in serted and soldered wires on both sides of the feed through holes soldered passive components resistors capacitors etc on both sides of the board and used Molex connecto
167. uts can operate external electronic devices Remote control of lamps and appliances is an additional capability of the ADC 1 via signals The Computer Journal Issue 21 transmitted over AC wiring to line carrier remote control modules of the BSR X 10 system i Single quantity price is 449 from Remote Measurement Systems Inc 2633 Eastlake A ve East Suite 206 Seattle W A 98102 phone 206 328 2255 Universal MAC INKER Computer Friends has announced the new Universal Cartridge Ribbon Re Inker Now one Mac Inker re inks just about any fabric ribbon cartridge available currently or in the future They claim that operation is ex tremely simple and wholly automatic and that their new formula lubricated carbonless ink yields a printout darker than many original ribbons They fur ther state that a good quality ribbon can be re inked up to 80 100 times depending on its original length The Mac Inker can also be used to ink and then re ink blank cartridges in any of 6 brilliant colors or combinations thereof Red Blue Green Brown Yellow or Purple using the new Com puter Friends ink The real time clock card for the Apple features PRODOS APPLEWORKS ond DOS 3 3 compatible 8 24 hour and 12 hour AWPM formats Time increments of 1 millisecond to 99 years Automatically time and dote stamps your files Powerful on board High capacity LITHIUME coincell batte Displays the date and time on
168. with emphasis on graphics and instrument control They state that it is the only language for PC s with built in GPIB syntax for both graphic and instrument type peripherals It permits easy adap tion of software written for HP and Tektronix engineering computers to the PC environment TBASIC s enhan ced instruction set conforms to the new ANSI proposed standard for BASIC and runs on many popular operating systems including PC DOS MS DOS CPIM UNIX and VMS Some of the supported computers include IBM PCIXTIAT AT amp T 6300 HP 150 amp In The Computer Journal Issue 21 tergral Tektronix 6130 amp 4170 and DEC VAX and Rainbow TBASIC has a unique assortment of user friendly features such as an on line HELP facility cross reference facilities for listing variables and referenced line numbers a command for renaming program variables that aids in documenting new and existing programs by making simple variable names more meaningful MOVE and COPY commands that enhance program editing capability by assigning new line numbers intelligently and syntax checking that is performed automatically as lines are entered to give instant feedback TBASIC features a full compliment of binary scalar array matrix and scientific math including standard trig transcendental and other functions using both integer and double precision floating point data types It also sup ports 8087 coprocessors Special array functions perform
169. y and the program re compiled for testing To make the changes permanent in your source code however use Wor dStar or VDO or some other Start Write t 2 4 Write Channel to read 8 to stop Read Channel If Channel 8 then goto Stop ritet Readin 355 If J then goto Stops ritelni GetTime Tine Val T ee Star tBecondu Code StartSecondu StartSeconde 6 645 BtartSeconds 7 2 5 Writeln Started at 31 t clear screen How many samples 1 16 806 5 For I 1 to J Do Bufferti Analogin Channel SGetTiee Ti se Val Time StopSeconds Code 5 Writeln Stopped at StopSeconde 7 2 8 Elapsed StopSeconds StartSecondss Writeln Elapsed times Elapsed 7 2 Seconds Samples Ji Writeln Saeple Rate Samples 7 Elapsed 7 2 Sasples Second J J Write How many saaples to display lt RET gt for all D Readin 3 5 Writeing For I ie 2 to J Do Write Buf ftert I2 Writelnt Calcul ateSt andar dDevi atians e Write Sample sean Saepietiean 7 2 4 Writeln Standard Deviation StandardDeviation 7 2 8 Write J Press lt RETURN gt to continue 5 Read J 5 Geto Start Stop End editor to alter the source This gets a little tiresome load the editor change the program load MTBASIC compile crash load the editor change the program But the result will be a source that hasn t bee
170. you only want to do occasional unsoldering To solve this I made my own simple type of Helping Hands all I did was cut two pieces of white pine any other wood will do one piece is the base and measures 4 wide by 9 long and is 4 thick the other is 2 12 wide 9 long and 2 thick all the dimensions are variable use whatever Stock you happen to have Glue and screw the narrower piece to the wider one along the 9 length to form a right angle Now take two wooden spring type clothespins and drill one or two holes in one leg of each use small wood screws and a little glue and attach these to the narrow piece spaced about 4 to 5 apart This device will hold a circuit board up for inspection and work and you can also leave the board in it and tip it over so that the weight of the holder keeps the board from sliding about Let your imagination run wild and make similiar holders for whatever size and shape of boards you work with The Art of it All Having talked about the unsoldering tools of the trade we now arrive at the larger issue of the art of it all Knowing The Computer Journal Issue 21 heating it with the soldering iron when to unsolder how to unsolder how to avoid damage when to deliberately cause damage It is now time to talk about the special theory of unsolderability What you never heard of this theory before Well that s because I just made it up No seriously we can express this asa
171. your specific routines in assembly We have a copy of this for review and will have more to say about it later Turbo Pascal As you can tell from reading this I ve been doing a lot of thinking about languages I haven t had time to do much programming but I have been thinking about it while doing other things When I first saw Pascal I decided that it had nothing to offer and I completely ignored it but I recently tried Turbo Pascal from Borland and it changed my mind about Pascal There has been a lot written about Turbo Pascal so I won t re hash it but you should be aware of its editor with WordStar like comman ds ability to run programs from memory compile directly to disk in one step and a very helpful error detection and correction system Jerry Houston s article in this issue is the first of a series on Turbo Pascal and we are interested in additional ar ticles from other authors We d like to hear from you if you have an article in mind and we d also like to publish short notes letters information on public domain software tips routines or questions on Turbo Pascal CP M is Dead Long Live Z We have been told that Digital Research has classified their products A D according to how much support the products will receive with D being the category with the least support Concurrent CP M is in group D and CP M Plus is in group C which means that in effect there is no support Ap parently they have also dis
172. zontal position is the first parameter in the parentheses following the procedure name GOTOXY and the vertical position is the second parameter Consider a program that needs to ask a large number of questions and get a lot of answers from the operator In stead of displaying questions one at a time and prompting individually for the answers the programmer might prefer to display all the questions on the screen at one time then move the cur sor to the position following each question and ask for the answers one at a time To put the cursor in the tenth horizontal position of the fifth screen line the procedure would be called by code such as GOTOX Y 10 5 Read Answer Consider now that an invoice is to be written and you need the PRINT HEAD not the cursor to go to a par ticular position on the paper before printing The answer is to write a i suitable procedure then save it ona disk for future use whenever you need the same feature The following exam ple which works with the Kaypro Juki printer can be modified easily for prin ters that use other control codes for print head movement Procedure PrintAt X Y Byte Begin Write lst 27 9 chr X Write lst 27 11 chr Y End The first line identifies the code asa procedure and names it PrintAt The parameter list following the name shows that two parameters will be passed to this procedure and locally calls them X and Y Each of these parameters

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