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Volume 3, Issue 3

1. 5 10 54 FE 3c 56 E a 52 20 54 20 54 41 50 45 m 5 Ps 20 ER CD 46 45 20 45 4E 13 cD ca 20 cD C3 5B 3F 59 53 20 44 59 23 23 55 56 3D AF 2 cs 59 50 4F 20 20 48 54 45 41 55 4 20 56 45 4E 45 75 E Ps FE ES FC C9 32 n lt CD 69 20 54 20 m 57 4F 53 20 54 20 20 oD 41 52 51 49 A7 FA 32 46 41 41 20 52 48 FE 20 p ac 57 a 1B 2 lt 25 18 m 40 18 E Ps 55 E 46 45 20 41 54 20 56 46 41 4D m 2c 40 46 20 4E 20 44 45 B7 gt ac D7 OD 20 53 5 4D 48 ry 41 50 4c 4E 49 54 oD cD C3 p ac 59 59 54 20 55 52 20 CD 4E 54 45 53 54 54 3D 4E 59 5 lt 4E BS CD 90 CD CD 5 Q6 FD E Ps 54 41 a 53 49 45 24 a 45 41 59 4E EN a lt BS F7 20 49 20 a 20 F5 D7 3D 45 45 m ac 20 48 4E 2 lt 41 50 E 4i FR 5 Ps F5 75 co FC cD 78 3C 56 50 20 4E 20 20 4E 55 52 49 20 47 20 56 47 20 o3
2. E MICRO 80 WINCHESTER DISK SYSTEM 5 000 000 BYTES OF HARD DISK STORAGE FOR MODELS 2 amp 3 Also in this Issue PROGRAMMING The Theory and Techniques of Sorting Part 4 Better BASIC Programming Part 7 Using the Level Array SOFTWARE Screen Copy Utility eFlashing Message Routine el ongvars Use Long Variable e he Mind Reader Names in your Basic Programs e Australian Income Tax Calculator ABOUT MICRO 80 EDITOR IAN VAGG ASSOCIATE EDITORS SOFTWARE LEVEL I MICHAEL SVENSDOTTER SOFTWARE LEVEL 11 CHARLIE BARTLETT HARDWARE EDWIN PAAY MICRO 80 is an international magazine devoted entirely to the Tandy TRS 80 microcomputer and the Dick Smith System 80 Video Genie It is available at the following prices 12 MONTH SUB SINGLE COPY MAGAZINE ONLY 26 00 2 50 CASSETTE PLUS MAGAZINE 65 00 4 00 cass only DISK PLUS MAGAZINE 125 00 10 00 disk only MICRO 80 is available in the United Kingdom from U K SUBSCRIPTION DEPT 24 Woodhill Park Pembury Tunbridge Wells KENT TN2 4NW Prices MAGAZINE ONLY 16 00 1 50 CASSETTE PLUS MAGAZINE 43 60 NIA DISK PLUS MAGAZINE 75 00 NIA MICRO 80 is available in New Zealand from MICRO PROCESSOR SERVICES 940A Columbo Street CHRISTCHURCH 1 N Z Ph 62894 Prices MAGAZINE ONLY NZ 43 00 NZ 4 00 CASSETTE PLUS MAGAZINE NZ 89 00 NZ 5 00 DISK PLUS MAGAZINE NZ 175 00 NZ 15 00 MICRO 80 is despatched from Au
3. Since LD is in fact copy instruction the original remains undisturbed and ready for continued use 0000900000 FLASHING MESSAGE ROUTINE L2 16K by A Park If you have ever wanted to draw attention to a particular piece of information within a program when the screen is packed full of data the answer is to make the important line s flash This can be achieved by using BASIC statements However they waste a lot of memory especially if you want to use the keyboard and flasn tne message at the same time VOLUME 3 NO 3 FEBRUARY 1982 MICRO 80 PAGE 24 This program flashes any one line message at a specific rate without being under BASIC program control It might just be the finishing touch to your programs more impressive especially when you find that after typing BREAK LIST and NEW the message is still flasning This makes it the ideal program to flash rude messages at your mother in law as she won t know how to turn it off Two commands have been included to allow the user to stop or start the program after it has been initialized Typing KILL then ENTER NEWLINE whilst in BASIC will stop the program and typing LOAD will re initialize it Disk BASIC users will obviously have to be content with continuous operation For those of you with good memories no pun intended a reasonable amount of the program should look familiar The reason for this is that it is designed around Eddy Paay s Curs
4. 15 Q6 Di lt 52 F9 B8 Ps B7 86 cD 32 FA FS 50 20 46 41 20 52 52 20 48 54 42 55 20 45 4D 45 41 20 4c 49 20 20 43 4E 55 55 43 4E 4C 52 54 52 gt 2 552959 20 4 FCDO FCEO 2 Jug A 58582055525 gap mmmmm D O0 YN F DRC FDC 7 FDE FDF m 2 FE1 FE2 FES FE4 m e FE6 FE7 CD FE9 FEA mmmmm DOM MM Mm Tm IO 956909055556 555953555505005355 7 2 FFI SF 13 41 20 43 48 49 52 a CD 13 45 50 49 57 53 53 oD C3 r 5 46 54 2 lt 54 54 4F 5 ac 49 20 55 41 50 4C x B7 cD 55 55 53 1 59 32 SE CD AF 1B 13 FE CD 9 20 4F 54 54 4 53 55 55 41 45 AF 45 50 75 53 43 54 52 20 7E FS FE 45 2 lt 54 41 59 gt ac 4D 57 20 20 45 20 18 FE 01 75 FE 23 23 FE SF m Ps 40 20 45 45 45 45 45 20 52 20 20 4c 47 59 3E 47 E 20 49 48 56 4i D7 41 ES a 20 45 4F 5 a 20 48 49 20 54 34 D7 32
5. you see that this is the better alternative Yes I know NEWDOS has the BREAK on off facility and you may say why bother to POKE The reason is that I hope you ve learned something 1 ON ERROR GOTO 32700 TELLS WHERE TO GO WHEN AN ERROR IS DETECTED 2 POKE 16396 195 16597 49 POKE 16398 4 TELLS BREAK KEY WHERE TO GO 26 R 45 DEMONSTRATES A DDIVIDE BY ZERO ERROR 27 RERE gt DEMONSTRATES A SYNTAX ERROR 3 PRINT PRESS BREAK KEY TO STOP THIS s GOTOSe THIS IS ONLY A DEMONSTRAT ION LINE 32700 IF ERR 2 1 12 THEN PRINT PRINT PRINT BREAK KEY WAS PRESSED PRESS BREAK K EY AGAIN TO STOP PROGRAM NOW OR PRESS ENTER TO CONTINUE INPUTA RESUME HANDLES BREAK KEY 3271 2 1 HAS OCCURED IN LINE ERL PRESS ENTER TO CONTI NUE 3 INPUTA RESUME NEXT HANDLES ANY ERROR This is another method of handling BREAK And this in effect provides a function of ON BREAK GO TO It s not as neat as could be done by assembly but does illustrate another approach The whole idea is that the BREAK key will simulate an ID error which will not normally occur in the RUN mode So when one does it can only be because BREAK has been pressed The BREAK handling address 16396 9 has POKEd into it the address of the ID error entry point yet again found from the ROM Reference Manual So if we do nothing more BASIC will stop and provide a message ID ERROR IN LINE X But to prevent th
6. gt 2 0 dg e o gt 8 c m m rt 23 9 z 29 2 3 O 8 4 SS o 3 oh 8 2 ON N amp D D 92 8 3 5 83 2 2 5 5 919 33 088 8 9 oM mic Te m SO 2 S 94 5 d 8 69 d 2g F8 S 28 Sl 55 22 g o0 4 9 o v g 20 9 nm amp 3 55 2 2 66 5 2 889 904 Es 3 22 a 2 25 22 O DY mam zz Sf 22 E 5 59 29 ms 8 o 5 5 gt 8 a o 5 s ia LLL FOR THE FIRST TIME IN AUSTRALIA GENUINE TANDY TRS 80 MICRO COMPUTERS HARDWARE AND SOFTWARE AT GREAT DISCOUNT PRICES HOW TO ORDER 1 SELECT ITEMS FROM 1980 TANDY CATALOGUE 2 DEDUCT 10 FROM ADVERTISED PRICES 3 POST US YOUR ORDER STATING DESCRIPTION CAT No AND A CHEQUE OR MONEY ORDER SUBSCRIBERS OF to CONQUEST ELECTRONICS Ltd 212 Katoomba St KATOOMBA 2780 Please supply QTY DESC ADV PRICE WE WILL ATTEND TO YOUR ORDER WITHIN 7 DAYS 2 SUPPLY GOODS SELECTED FREIGHT FREE 3 SEND ADVERTISING REGULARLY TO KEEP Y OU INFORMED OF CURRENT SPECIALS subject to availability SUB TOTAL LESS 10 TOTAL FIND CHEQUE FOR SEND FREIGHT FREE TO ADDRESS hesitate inae DEALER CONQUEST
7. VOLUME 3 NO 3 FEBRUARY 1982 MICRO 80 PAGE 5 ARTICLES File handling on the 80 Description of the functions performed by the Expansion Interface Reviews of 80 compatible printers Reviews of commercially available software including that produced by us Reviews of commercially available hardware master index to the appropriate sections in the Tandy Manuals in Level I Level II DOS etc Comparative reviews of disk drives How to convert a Level I program to Level II A simple guide to using Level I Arrays An explanation of how to make full use of USR PEEK and POKE statements Discussion of the various electric fields produced by the keyboard tape recorder monitor disk drives etc how to measure them how important they are and how to combat them SOFTWARE A 1 program to enable the break key to work like RESET when using an expansion interface Stock market program Horse racing system Morse code decoder Sub routine Forum A new STAR TREK game Modification to SCRIPSIT which will enable it to output to the SYSTEM 80 printer port Programs of pharmaceutical interest such as Pharmacokinetics Patient Medication Records Drug information services etc Multiple file tape backup as in Australian Personal Computing Aug Sept 81 for PET A PRINT SCREEN command for the Model I A football game using graphics and sound Graphics car race as seen from the driver s positio
8. dump of LONGVAR RT F400 END FF14 ENTRY F9A4 20 F9 40 11 64 OO 19 22 O2 F3 23 36 FF 2 22 OA F3 21 76 FS 22 AS F4 CD 89 F9 21 O OC F3 E1 Ci 31 OO F3 C5 ES AF 67 6F 39 2 OO 54 SD 1B ED B8 AF 32 40 F3 21 7E R9 22 22 SB F7 C 20 44 40 2B 81 32 SF SC 2B 11 4D F4 DS D7 DA 6C OE FS 46 B7 CC E4 F4 78 28 40 FE 2E 6 OE FE 26 94 41 FE CA FA FE 93 CA 07 1F FE 22 28 2B FE 88 CA O5 1F FE D6 28 2E B7 28 41 23 FE 9A O6 1E FE 99 CA 1E FE 98 OO 1E FE 9B 09 1E 2B CD 3D 1E 2 2B C2 76 FS 01 22 OO D7 BS 23 2B 18 F7 23 7E FE CF CO O1 4 CF 23 7E B7 C8 R8 20 F9 24 7E B9 20 F8 23 C9 23 22 04 FZ 7E 23 6 28 68 23 7E 22 O6 F3 23 7E 32 07 F3 2 52 XC C9 ED SB O2 FS ES 21 1 FE FF 28 42 ED 53 00 F3 060 00 22 F3 13 Ei ES 1A B7 22 au as nr 4 4 99 ap ou oo us oo ar nnmnnn o O O a O F54 Fos F56 mm e a Own F59 FSA FSE FSC mo FSF F40 Ne F6z F64 nnmnnn O O Fg O UNCA F6A Q F6D F6E NO omn F71 F72 F73 NNN F77 F78 23 52 gt 22995 gt 5 gt gt 5 gt 5 gt gt gt 5 gt 52599925555 gt 25 gt 5 gt 55 gt 525902929525255595 gt 5992995 25 ao oo OO as op 88 OO op 88 48 48 gs 48 48 no 8 48 np ux np np no np np 38 no 88 np as 33
9. That is no comparisons approaches the order of n logon SELECTION SORT This algorithm was discussed in the second article of this series During the first pass in which the smallest item was found n 1 items are compared Therefore we can say that for the pth pass n p comparisons are required Also n 1 passes are required The total number of comparisons is therefore 1 2 3 2 1 gt n l where p represents the pass number 1 This represents the summation of an arithmetic progression of general formula 3 2A d N 1 where A first term d common difference N nth term n 1 In this example A d 1 N no of passes n 1 Substituting 1 1 E Cota 2 1 l n 1 1 n l 2n 2 n 2 2 1 As n becomes large 1 becomes insignificant Therefore no comparisons approx in gt which is of the order of n This is much less efficient than one to the order of n logon TO SUMMARIZE Two further variations to straight insertion sorting were demonstrated one using a data structure based on linked organization using a linked linear list the other involving comparison of items that are separated by a diminishing increment t can be shown mathematically that the efficiency of this and like algorithms is greater than some of the more elementary algorithms discussed earlier like the selection sort Well this finalizes the discussion on sorting
10. 30 5 46 61 62 15 14 29 30 45 46 61 62 21 22 29 30 55 54 61 62 37 38 45 46 55 54 61 62 PRINT9O TAB 15 T MIND READER S STRINGS 28 129 RETURN 15 51 47 15 51 47 59 47 55 1 COPYRIGHT BY DAVID WEAVER REM 11 PINE GROVE SALE VICTORIA 3850 051 445019 REM O3 APRIL 1981 REM PROGRAM TO COMPUTE NET INCOME AND TAX PAYABLE DIM LL 4 TD 4 TC 4 A 2 1 4 1HHHHHHE HH CLS PRINT 915 PERSONAL INCOME AND TAX PAYABLE 90 REM COMPUTES NET INCOME 100 PRINT PRINT INPUT WHAT IS YOUR GROSS INCOME FROM GROUP CERTI 3GC 110 PRINT INPUT ANY OTHER INCOME 7 OI 120 PRINT PRINT YOUR TOTAL INCOME IS USING A GC OI 130 PRINT INPUT WHAT ARE YOUR TOTAL DEDUCTIONS DD 140 GC OI DD 150 PRINT PRINT YOUR NET TAXABLE INCOME IS USING 4 160 PRINT INPUT WHAT IS THE TAX PAID FROM YOUR GROUP CERTIFICATE S TP 170 REM PROGRAM TO FIND TAX PAYABLE ON NET INCOME 180 REM LL STORES LOWER LIMIT OF TAX SCALE TD STORES TAX DOLLAR ON LOWER LIMIT 190 REM TC STORES CENTS IN THE DOLLAR ON NET INCOME OVER THE LOWER LIMIT 200 REM INPUTS TAX SCALES 210 FOR J 1 TO 4 220 READ LL J TD J TC J 230 NEXT J 240 RESTORE 250 REM SEARCH FOR FIRST VALUE IN LIST LL WHICH EXCEEDS TI 260 FOR J 1 TO 4 270 IF LL J gt TI THENGOTO310 280 NEXT J 290 LET 1 5 REM PRINT OUT INCOME TAX
11. 57 59 61 63 1030 RETURN 2861 AuWNusas ON SWNTOA 08 0 91 39Vd 1040 1050 1060 1070 1080 1090 1100 1110 1120 1130 1140 1150 1160 1170 1180 1190 1200 1210 1220 1230 1240 1250 1260 1270 1280 1290 1300 1310 1320 1330 1340 1350 1360 1370 1380 1390 1400 1410 1420 1430 1440 1450 1460 1470 1480 1490 1500 1510 1520 1530 1540 1550 N 1560 END PRINT2448 PRINT 2 PRINT PRINT 18 PRINT PRINT 34 PRINT 5 RETURN END PRINT23448 PRINT 4 PRINT PRINT 20 PRINT PRINT 36 PRINT 52 RETURN END PRINT23448 PRINT 24 PRINT PRINT 40 PRINT 56 RETURN END PRINT23448 PRINT 16 PRINT PRINT 24 PRINT PRINT 48 PRINT 56 RETURN END PRINT23448 PRINT 32 PRINT PRINT 40 PRINT PRINT 48 PRINT 56 RETURN END PRINT9395 IS THE NUMBER YOU SELECTED LISTED RETUR 5 19 55 51 a 5 21 37 55 9 25 21 57 17 25 49 57 49 57 6 22 ig 54 6 N 58 54 10 26 42 Sg 18 26 50 58 50 58 7 40 23 26 39 42 55 58 7 4412 23 28 59 44 55 60 11 12 27 28 45 44 59 60 19 20 27 28 517 952 59 60 35 36 4 51 52 59 60 11 14 27 30 46 59 62 13 14 29
12. Even so the speed required is too high for a program such as this to be written successfully in BASIC 1 CLEAR15 FORI 11072 READD S S CHR D NEXT SL PEEK VARPTR 5 1 SM PEEK VAR PTR 5 2 POKE16526 SL POKE16527 SM DATA2 5 127 1 203 124 40 4 34 28 65 201 34 39 65 DATAZ19 255 31 31 31 47 23 248 95 58 57 65 254 4 32 2 2 DATA1I71 95 59 32 65 87 237 75 28 65 43 124 181 4 6 DATAZ 21 227 271 227 24 12 42 30 65 122 7 7 87 23 3 179 DATAZ11 255 5 12 177 32 228 123 211 255 201 INPUT WHAT TYPE OF SOUND 1 TO 10 4 IFT lt 10RT gt 1 THENPRINT MUST BE BETWEEN 1 1 GOTOSELSEONTGOTOS6 7 8 9 1 11 12 13 14 15 5 GOTOA 6 T 1 G0TO16 7 T 5 80T016 T 6 60TO016 9 T 17 G0TO016 16 T 18 GOTO16 11 T 22 G0TO16 12 25 16 15 86 GOTO16 14 T 9 GOTO16 15 T 102 G0TO16 VOLUME 3 NO 3 FEBRUARY 1982 MICRO 80 PAGE 10 16 POKE16672 T 17 INPUT DURATION 1 TO 52767 0 IFD lt 10RD gt 32767 THEN 7ELSED D 32768 X USR D 18 INPUT PITCH 41 100 5P X USR P R INPUT DO YOU WANT TO REDEFINE TYPE R IFLEFTS R 1 Y THENSELSEINPUT DO YOU WANT TO REDEFINE DURATION IFLEFTS 1 Y THEN1 7ELSE18 This is a more complex sound generation program but it still relies on the principle explained above it must if it s to use the cassette port I won t attempt an explanation of this code it s not exactly elementar
13. and if it is out of paper the value is less than 127 the printer is ready to roll If it is 127 then the printer is out of paper There is more information provided by this location but it is not the same for every printer so the best way is to experiment and find out the status checks for yourself The floppy disk control circuitry mainly consists of the Western Digital 017718 floppy disk controller which is detected by the Microsoft ROM s test routine and instructed to coimnence loading the Disk Operating System DOS if BREAK is not pressed to generate a forced jump to LII The Expansion Interface then accepts the data and control information is passed to the floppy disk through the DOS The extra RAM is straightforward simply being an extension of the keyboard RAM with the exception of the more complicated addressing techniques made necessary by the limited number of pins on tne card edge The 25ms interrupts are not used by LII and the interrupt routine automatically returns without doing anything This useful feature of the Z 8 is however exploited to a small extent TRSDOS and to a larger extent by NEWDOS8 and other DOS s TRSDOS it is used for the real time clock and in 8 its full potential is used to check for the triple key depressions and for the print spooler I own a 16K LII with lowercase and an E I with 32K of MICRO 80 RAM along with two Tandy drives and Microline 80 printer and I have f
14. by insertion although this is by no means all there is to insertion sorting There are many other hybrid algorithms that employ a mixture of techniques endeavouring to obtain the best features of insertion exchange selection and merging techniques Next month a very efficient form of sorting by selection more so than the Shell sort will be discussed due to the use of yet another Kind of data structure 000000000 VOLUME 3 NO 3 FEBRUARY 1982 FARE The following is a list of 80 Users Groups it so that we can publish details MICRO 80 PAGE 16 180 USERS GROUPS ex If you have a group that is not included here please let us know about Owners of System 80s are welcome at all the groups AUSTRALIA AUSTRALIAN CAPITAL TERRITORY CANBERRA GROUP Contact Bill Cushing 10 Urambi Village Kambah ACT 2902 MEETINGS 3rd Thursday of each month at 7 30 p m in Urambi Village Community Centre Crozier Circuit Kambah NEW SOUTH WALES COMPUTERTOWN CAMDEN CTAUS Keith Stewart P 0 Box 47 Camden NSW 2570 Contact SYDNEY MAPPER CP M GROUP Dan Lawrence Mapper CP M Users Group c o G P 0 Box 2551 SYDNEY NSW 2001 Contact SYDNEY EASTERN SUBURBS Contact Dan Lawrence TRS 80 Eastern Suburbs Group c o G P 0 Box 2551 SYDNEY NSW 2001 WOLLONGONG GROUP Contact Paul Janson P 0 Box 397 DAPTO NSW 2530 BLUE MOUNTAINS OF N S W Contact Greg Baubman Te
15. x DESCRIPTION OF THE FUNCTIONS PERFORMED BY THE EXPANSION INTERFACE by Andrew Jack The Expansion Interface for the TRS 80 performs five main user accessible functions A relay to provide two cassette ports A centronics parallel printer port A floppy disk controller and support circuitry Provision for an extra 32K of RAM 25ms interrupts real time clock mannna 1 2 3 4 5 Vw The relay which selects the cassette port is accessible through memory location 37E4H 14308 using 14308 0 cassette one is selected normal and 143 8 1 selects cassette two This function has more possibilities than are immediately obvious for example by shorting pins one and three on the Expansion Interface cassette input and connecting a low powered circuit to pins one and three of cassette output port two it is possible to close the connected circuit by a simple 0 14308 1 and open it with 43 8 7 Similar results can be obtained by using the relay inside the keyboard but it is only suitable for very low power use and has a tendency to weld shut and also to revert to open when in BASIC command mode VOLUME 3 NO 3 FEBRUARY 1982 MICRO 80 PAGE 23 The printer port is a straightforward centronics parallel port driven by the LII ROM printer driver and simply transmits data when a READY status is shown in location 37E8H 14312 This location can be PEEKed to show whether a printer is connected
16. 205 300 375 LOADING LONGVAR With NEWDOS Type BASIC 62464 Load in the BASIC program to be worked on Type CMD LONGVAR CMD The LONGVAR menu will then be displayed and you can use the functions you require With TRSDOS Type LOAD LONGVAR CMD Type BASIC Answer MEMORY SIZE with 62464 Load in the BASIC program to be worked on Type SYSTEM In response to the next prompt type 63908 The LONGVAR menu will then be displayed and you can use the functions you require 0000000000 xxxx THE MIND READER by P J Smith Is this Artificial Intelligence or just computer trickery Well you might be able to deceive your computer illiterate friends or sceptical relatives The mind reader is simple fast and entertaining Simply think of a number the computer will show you several lists of numbers and will then ask you if you see the number you thought of THEN it will stare at you very deeply and will tell you the number you picked and it s right EVERY time The Mind Reader does not reveal his tricks but you should be able to unravel the mystery by studying the program listing 0000000000 AUSTRALIAN INCOME TAX CALCULATOR 12 4 by D Weaver In Australia every citizen is required to lodge a Taxation Return during the month of July each year in which he or she discloses all earnings for the preceding financial year July to June 30 Yes we know there are exceptions but we don t need to go into
17. 4200H disk operating system For almost the first time in Australian microcomputing history you can purchase a significant item of hardware for the same price in Australia as can Americans If you are considering using a TRS 80 in a business application I believe you should very seriously consider including the Micro 80 hard disk sub system as part of your system The minimum specification computer you require for its proper use is a 48K single disk drive TRS 80 Model III or a 64K Model II You could therefore have a5 Mbyte hard disk CP M Model III single floppy disk drive system for only 5895 00 Micro 80 prices That is little more than half what you would pay for any other hard disk computer system An added advantage is that absolutely no modifications are needed to the Model III The Micro 80 sub system simply plugs onto the 50 way expansion connector on the bottom of the Model III Tandy s warranty is unaffected Using CP M you will have access to a wide range of professionally written and fully supported applications programs including accounting packages word processing finance and budgeting high level languages etc etc To add even further support Micro 80 has commissioned Micro Systems Software in the U S A to develop a version of DOSPLUS 4 0 especially for this system With DOSPLUS the sub system will have access to the full range of Model III programs Perhaps the best news of all is that we are offering a 30 day money back tri
18. 450 IF E Y THEN 480 460 X 0 470 GOTO 490 480 X 8 490 CLS 500 IF A 5 THEN 720 510 GOSUB 1350 GOSUB 1560 520 PRINTTAB 23 LIST NO 5 530 GOSUB 1550 540 F INKEY IFF THENS40 550 IF F Y THEN 580 560 570 GOTO 590 580 16 590 CLS 600 IF A 6 THEN 720 610 1450 GOSUB 1560 620 PRINTTAB 23 LIST NO 6 630 GOSUB 1550 640 H INKEY IFH THEN640 650 IF H Y THEN 680 660 7 0 670 GOTO 690 680 7 52 690 CLS 700 IF A 1 THEN 720 710 IF A gt 1 THEN 110 720 460 LOOK ME CLOSELY WHILE I READ YOUR MIND 730 FOR Q 1 TO 1000 NEXT CLS 740 M U V W X T Z 750 9465 TAB 13 I HAVE IT THE NUMBER YOU SELECTED WAS 760 PRINT FORT 1TO1000 NEXT 770 PRINT M 780 PRINT 790 PRINT TAB 20 TELL ME WAS I CORRECT J INKEY IFJ THENS8OO 810 IF J N THEN 880 820 PRINT30 TAB 19 I TOLD YOU I CAN READ MINDS 830 PRINT 840 PRINT WOULD YOU LIKE TO HAVE ANOTHER TRY 850 K INKEY IFK THENSSO 860 IF K Y THEN 20 870 END 880 CLS 890 9465 IMPOSSIBLE DO 0 MAKE MISTAKES 900 PRINT 910 PRINT YOU MADE AN ERROR LET S TRY AGAIN 920 FOR X 1T02000 NEXT CLS 950 GOTO 20 940 END 950 PRINT23448 960 PRINT 1 5 5 7 9 11 15 15 970 PRINT 980 PRINT 17 19 21 25 25 27 29 51 990 1000 PRINT 33 35 37 39 41 45 45 47 1010 PRINT 1020 PRINT 49 51 55 55
19. 64 15296 LSB ADDRESS AND 255 MSB INT ADDRESS 256 17 POKE 32557 LSB POKE 32558 MSB POKE 32569 LSB POKE 32576 MSB POKE 32596 LSB POKE 32597 MSB The BASIC program which is LISTed after the machine language source code is used to change the flash rate of the message if desired Rates of less than 100 tend to make the display a little hard to read due to keyboard scanning Both programs do NOT have to be in the computer at the same time as the flash rate is set to a default value of 592 Dec by the machine language program 0000000000 VOLUME 3 NO 3 FEBRUARY 1982 MICRO 80 PAGE 25 LONGVARS L2 48K by R T Worley One of the limitations of the MICROSOFT BASIC used 80 microcomputers is the restriction placed on variable names It can be very helpful when writing a program to use meaningful words as variables such as LENGTH or WIDTH or perhaps MIDDLE These words make the program logic much easier to follow and the BASIC code is to an extent self documenting This approach is possible on the TRS 80 but with two important restrictions The variable name must not contain any reserved words such as LEN and MID in the examples above and the interpreter recognises only the first two letters of the variable name This means that the first two letters in each long variable name used must differ from all others In practice these two limitations are so restricting that only the most intrepid programmers use long variable names i
20. 789 microcomputer for this purpose When the new 51 Winchester Technology drives first became available in the U S A about 12 months ago ACT decided that these would be ideal for their systems but no suitable disk controller board was available Ken Utley of ACT rose to the challenge and developed a controller board and software to interface to the Zenith 789 operating under CP M and thus was born the ACT 506 controller Australian Protection Industries Pty Ltd was the Australian distributor for the security systems developed by ACT hence the tie up Recently Ken Utley moved to Australia bringing with him the design rights for the ACT 506 and Australian Computers and Telecommunications now manufactures and exports ACT 506 control ler boards all over the world including the U S A In the intervening period Ken has developed the software and hardware to interface the ACT 506 to a number of different microcomputers including the North Start Horizon the Superbrain S 100 systems and most importantly from our point of view the TRS 80 Models II and III If you closely examine the the photograph on the front cover of the hard disk sub system you will see that it bears the Micro 80 insignia This is because we are so impressed and excited by its performance that we have had ACT construct the unit for us We have also negotiated a special price of 2 995 00 tax included for a complete sub system for the TRS 80 Model III together with the CP M org
21. 7F2C 21003C 00750 PRINT LD HL VIDEO TOP LEFT OF SCREEN 7F2F 7E 00760 LD A HL 7F30 00770 CP SPACE IS MESSAGE PRINTED 7F32 201B 00780 JR NZ MESOFF YES TURN IT OFF 7F34 21717F 00790 LD HL MESAGE THEN PRINT IT 7F37 DD21003C 00800 LD IX VIDEO 7F3B 32F57F 00810 LD TEST 7E 00820 LOOP LD A HL FEOO 00830 CP CHECK FOR END OF MESSAGE 7F41 2808 00840 JR Z ENDMES 7F43 007700 00850 LD IX A 7F46 23 00860 INC HL 7F47 DD23 00870 INC IX 7F49 18F3 00880 JR 1 KEEP ON PRINTING 7F4B AF 00890 ENDMES A 7 4 FS 00900 PUSH AF 7F4D 1819 00910 JR FIXCNT FIX COUNT AGAIN 7FAF 21B27F 00920 MESOFF LD HL CLEAR WIPE OUT MESSAGE 7F52 DD21003C 00930 LD IX VIDEO 7F56 7E 00940 LOOP1 LD A HL 7F57 FEOO 00950 SAME AS BEFORE 7F59 28FO 00960 JR Z ENDMES 7F5B 007700 00970 LD 1X A 7F5E 23 00980 INC HL 7 5 DD23 00990 INC IX 7F61 18F3 01000 JR LOOP1 7F63 F5 01010 RESCNT PUSH AF 7F64 AF 01020 XOR 7F65 32F57F 01030 LD TEST A 7F68 215002 01040 FIXCNT LD HL DELAY GET DELAY 7F6B 22F37F 01050 LD COUNT HL F1 01060 POP AF D9 01070 EXX 7F70 C9 01080 RET 01090 01100 CHOOSE YOUR OWN MESSAGE HERE 01110 N B FIRST CHARACTER MUST NOT BE A SPACE 01120 7F71 3D 01130 MESAGE DEFM SYSTEM 80 16 LII COMPUTE R SYSTEM 7FB1 01140 DEFB CONFIRM END OF MESSAGE 7 2 20 01150 CLEAR gt CLEAR WITH 64 SPACES
22. 7FF2 00 01160 AS BEFORE 7FF3 0000 01770 COUNT DEFW 7 5 01180 TEST DEFB 01190 01200 THIS SECTION RESETS KEYBOARD VECTOR 01210 7FF6 21 505 01220 KILL LD HL KBSCAN 7FF9 221640 01230 LD KBVEC HE 7FFC C3CCOS 01240 JP BASIC 01250 01260 THIS SECTION RUNS THE PROGRAM BY ITSELF 01270 4015 01280 ORG 4015H 4015 1 57 01290 LD BC 7EESH 7EES 01300 END INIT INIT IS A BACKUP 77 10 FLASH RATE DRIVER FOR MESSAGE ROUTINE XX kk 20 CLS 448 PRESENT FLASH 5261 7 PEEK 32618 256 40 PRINT PRINT 50 INPUT ENTER NEW FLASH RATE 60 IFR gt 32767THENR 32767 70 IFR lt OTHENR 100 POKES2617 RAND255 POKE32618 R 256 AND255 90 60 010 100 END 22595555259 4 O vJ 90 Hex STA mmmmmm F46 F47 MOO MND O 0000000000000000 FAF C N J COLEMAN 6 13 HOWITT ST SOUTH YARRA VIC 2141 xxx SCREEN COPY UTILITY gt CLS POKE 16553 255 FIX BUG FOR X 31690 TO 31740 READ A POKE NEXT X ONERROR GOTO 175 DEFUSR 21690 GOTO 180 POKE 16526 202 16527 122 XX USR DATA 33 225 123 62 195 50 151 65 34 152 65 33 239 123 50 DATA 154 65 34 155 65 195 204 6 229 33 0 60 17 253 123 1 0 DATA 4 237 176 225 201 229 33 2535 123 17 9 60 1 0 4 DATA 237 176 225 201 END
23. A C M This states that X pair swaps as above can be substituted by one save X 1 moves and one insertion of the saved item This coincides exactly with the method of rearranging an item ranked in the straight insertion sort It can be seen from this code that the diminishing increment DI in line 4120 starts at half of the list size and diminishes by a factor of 5 for each successive pass This has the effect of increasing tne pass size in line 4140 from half of the list size to 1 less than the list size MATHEMATICAL ANALYSIS The diminishing increment sort is among many other sorting algorithms whose efficiency approaches N Log of N to Base 2 This sorting algorithm has been chosen te demonstrate that fact because the number of passes and comparisons in each pass can be easily seen For instance with a list size of 16 the number of passes 4 because the DI diminishing increment starts at 8 and is modified to 4 2 and 1 This means that the minimum number of comparisons in each of the passes are 8 12 14 and 15 as the pass size increases in the same proportion that the DI is decreasing These represent the minimum number of comparisons because when an out of sequence situation is detected further comparisons and moves are made before continuing with the pass fact the total number of passes involved P is related to the list size through the relationship 2P N A list size of 32 requires 5 passes 25 32 i e pass
24. PAYABLE ON NET INCOME TI 310 IT TD J 1 TC J 1 TI LL J 1 320 PRINT PRINT INCOME TAX PAYABLE USING A 330 IF IT gt TP THENGOTO370 340 REM PRINTS OUT WHO OWES WHO 250 PRINT PRINT THE TAX DEPARTMENT lt OWES YOU gt USING A INT TP IT 005 100 7100 360 GOTO38O 570 PRINT PRINT lt X YOU OWE gt THE TAX DEPARTMENT USING AS CIT TP 005 100 100 380 INPUT DO YOU WANT TO CONTINUE 32 390 IF LEFT Z2 1 Y GOTO7O ELSECLS END 400 REM IF TAX SCALES CHANGE ALTER VALUES IN DATA LINES 410 DATA 1 0 0 420 DATA 4041 0 0 32 430 DATA 17259 4225 56 00 46 440 DATA 54478 12155 5 0 60 UNTUP 1 hj 2020025020520 2861 Auynug34 OM 08 OUIIN 39Vd VOLUME 3 NO 3 FEBRUARY 1982 MICRO 80 PAGE 35 NEXT MONTH S ISSUE Next month s issue will contain at least the following programs plus the usual features and articles LEMNISCATES 111 4 This program is for all those people who hate typing in long program listings Lemniscates has one 1 line yes that s all The author wanted to see just how much could be done in one line of program If you know what Lemniscates are you will have an idea just how much this one line program does If you don t know look it up before the next issue WHEEL LOADER PRODUCTION LI 4K This program is designed to calculate wheel loader production tons hour It ca
25. Program allows copying of files larger than the floppy disk drive capabilities RESTORE Program retrieves large files from format written by SAVEFILE What of the TRS 80 Model I and System 80 It is a relatively straightforward matter to implement the hard disk sub system on these computers if the demand is there If you are seriously interested in having 5 Mbyte of fast reliable storage on your Model I or System 80 write in and let us know so we can decide whether we should implement it or not 0000000000 INPUT OUTPUT From R J Maclean Formartin Qld I have recently typed in the Sound Effects Revisited program which was published in the September edition During the typing in I came across a bug which may also be a potential problem in other programs When I ran the program my computer System 80 threw up a SN ERROR IN 580 After examining the relevant line I came to the conclusion that the lack of a space was causing the problem Accordingly I changed the line from 580 IFM gt LETHENM 1 to 580 THENM 1 The changed line ran properly Perhaps the removal of all blanks outside of REMark and PRINT lines is not always the best course As I am renewing my subscription with this letter I will take the opportunity to state that I have found Micro 80 to be very helpful and educational The particular bug you discovered was probably due to the variable LE and the THEN statement forming the reserved
26. Rodney in the Community Recreation Hall Macdonald Street Lindum Street Yokine UNITED KINGDOM NATIONAL NATIONAL USERS GROUP TANDY OWNERS PROGRAM amp INFORMATION CO OP Contact Brian Pain 40 High St Stoney Stratford Contact Derek Higbee 12 Shelley Close Ashley Milton Keynes Heath Ringwood Tel Ringwood 6720 CO DURHAM NORTH EAST TRS 80 GROUP NATIONAL NEWCASTLE PERSONAL COMPUTING SOCIETY Contact Barry Dunn 8 Ethick Tce North Craighead Contact John Stephen Bone 0632 770036 Stanley Co Durham DH9 6BE Tel 0207 30184 COMPUTERTOWN UNITED KINGDOM CTUK Contact Dave Tebbutt c o 14 Rathbone Place London W1P 1DE NEW ZEALAND AUCKLAND Contact Ron Feasy Bus 799 366 Home 469 455 MEETINGS 1st Tuesday of each month 7 30 p m at NZ Solenoid Co Ltd 28 Kalmia Street Ellerslie Auckland BOLTON NORTH WEST TRS 80 GROUP Contact The Secretary North West TRS 80 Users Group 40 Cowlees West Houghton Bolton BL5 3EG COMPUTERTOWN NORTH EAST CTNE Contact c o 2 Claremont Place Gateshead Co Tyne amp Wear NEB 1TL Tel 0632 770036 643417 679119 559167 EDUCATIONAL USERS GROUP Dave Futcher Head Teacher Beaconsfield First amp Middle School Beaconsfield Rd Southall Middlesex England Contact WEST HERTS 80 USERS GROUP Contact Terry Bradbury 20 Spruce Way St Albans Herts Tel PARK STREET 73663 MICRO 80 PRODUCTS DON T BE HEL
27. a long time to load in all the lessons however and for some time there has been a Readers Request to publish instructions for transferring this program and its data files to disk Mr Hilder has accomplished this task and describes this procedure as follows INSTRUCTIONS 1 Load the TOUCHTYPE tape into the recorder and adjust the volume control to a suitable level I advise you not to attempt the rest of the instructions until you are sure the tape will be read reliably 2 Place the recorder in the playback mode and CLOAD the first program 3 List the program to make sure the load was successful then type SAVE TTYPE1 BAS 4 Leaving the recorder in the play mode type NEW then type in and run the following program 18 CLEAR 1999 20 OPEN O 1 TTYPE3 TXT 30 INPUT 1 D 40 PRINT D 50 D CHR 34 D CHR 34 60 PRINT 1 D 70 CLOSE END VOLUME 3 NO 3 FEBRUARY 1982 MICRO 80 PAGE 22 The following message will be displayed and then saved on disk THHHHHHHHHHHHHHHHE THANK YOU 5 CLOAD the second program 6 Type SAVE TTYPE2 BAS 7 Load and run the following program 10 CLEAR 1299 20 OPEN O 1 TTYPE4 TXT 30 INPUT 1 A B D 49 PRINT A B D 5 D CHR 34 D CHR 34 60 PRINT 1 A B D 70 0009 You should see each block of data displayed on the screen and then saved to disk The total time involved will be about 20 mins but it is worth watching the proceedings
28. a number of small retail businesses in Adelaide It is therefore thoroughly debugged and has been tailor made to suit the requirements of a small business MICROMANAGE MENT SRC enables you to monitor the current stock level and reorder levels of 500 different stock items per tape or wafer It includes the following features new items to inventory Delete discontinued items from inventory List complete file Search for any stock number Save data to cassette or wafer Load data from cassette or wafer Adjusts stock levels from sales results and receipt of goods List all items requiring reordering We can thoroughly recommend this program for the small business with a L2 16K computer SCOTCH BRAND COMPUTING CASSETTES Super quality personal computing cassettes C 10 pack of 10 26 00 incl p amp p C 30 pack of 10 28 00 incl p amp p UTILITIES S KEY hy Edwin Paay 15 95 plus 50c p amp p S KEY is a complete keyboard driver routine for the TRS 80 and becomes part of the Level basic inter preter With S KEY loaded the user will have many new features not available with the standard machine S KEY features S KEY provides an auto repeat for all the keys on the keyboard If any key is held down longer than about half a second the key will repeat until it is released Graphic symbols can be typed direct from the key board this includes all 64 graphic symbols available from the TRS 80 S
29. are 28 cards displayed on the screen face down Players take it in turn to turn them over with the object of finding matching pairs There are 40 different patterns which are chosen at random so the game is full of end less variety This is of particular value in helping young children to learn the art of concentrating and at the same time to introduce them to the computer METEOR AND TORPEDO ALLEY L2 16K 10 95 60c p amp p Those who frequent games arcades will recognize these two electronic games In METEOR you must destroy the enemy space ships before they see you In its most difficult mode the odds are a thumping 238 to 1 against you being successful In torpedo alley you must sink the enemy ships without hitting your own supply ship Both games include sound effects and are remark ably accurate reproductions of the arcade games AUSTRALIAN SOFTWARE GAMES SHEEPDOG L2 16K Ever wondered how a sheepdog manages to drive all those awkward sheep into a pen Well here is your chance to find out just how difficult it is and have a lot of fun at the same time You control the sheepdog the computer controls the sheep As if that isn t enough look out for the dingoes lurking in the bush 8 95 60c p amp p U BOAT 8 95 60c p amp p Real time simulation at its best Comes with working sonar screen and periscope a full rack of torpedoes plenty of targets working fuel and battery meters helpful Mot
30. drives in the world MPI drives use the same form of head control as 8 drives and consequently they have the fastest track to track access time available 5msec All MPI drives are capable of single or double density operation Double density operation requires the instal lation of a PERCOM doubler board in the expansion interface As well as single head drives MPI also makes dual head drives A dual head drive is almost as versatile as two single head drives but is much cheaper Our MPI drives are supplied bare or in a metal cabinet set up to operate with your TRS 80 or SYSTEM 80 All drives are sold with a 90 day warranty and service is available through MICRO 80 PRODUCTS MPI B51 40 Track Single Head Drive only 349 MPI B52 40 Track Double Head Drive only 449 Prices are for bare drives and include p amp p Add 10 00 per drive for a cabinet and 60 00 for a power supply to suit two drives 40 track drives are entirely compa tible with 35 track drives A 40 track DOS such as NEWDOS 80 is necessary to utilise the extra 5 tracks OVER 800 KILOBYTES ON ONE DISKETTE WITH MPI 80 TRACK DRIVES MPI 80 track drives are now available The B91 80 track single head drive stores 204 Kilobytes of for matted data on one side of a 5 inch diskette in single density mode In double density mode it stores 408 Kilobytes and loads saves data twice as quickly The B
31. earthed soldering iron If you do not have the necessary experience equipment we will install the modification for you for 20 plus freight in both directions Make sure you arrange the installation with us first before despatch ing your computer so that we can assure you of a rapid turn around We are also arranging to have installers in each State See elsewhere in this issue for their names and addresses PRICES Cat No HD 020 Lower case mod kit for TRS 80 49 00 plus 2 00 p amp p HD 021 Lower case mod kit for SYSTEM 80 49 00 plus 2 00 p amp p EPSON MX 80 PRINTER ONLY 949 Inc Cable for TRS 80 and p amp p Printer only 940 incl p amp p The EPSON MX 80 printer is compact quiet has features unheard of only 2 3 years ago in a printer at any price and above all is ultra reliable All available print modes may be selected under software control Features include high quality 9x9 dot matrix character formation character densities 80 characters per line at 10 chars inch 132 characters per line at 16 5 chars inch 40 characters per line at 5 chars inch 2 line spacings 6 lines per inch 8 lines per inch 80 characters per second print speed bi directional printing logical seeking of shortest path for printing lower case with descenders TRS 80 graphics characters built in standard Centronics printer port The bi directional printing coupled with the logical seeking of the shortest print path whic
32. long to reproduce in the magazine Instead a hex dump has been printed Enter the hex listing using a suitable monitor such as BMON Issues 3 4 and 5 or ZMON from the MICRO 80 Software Library Vol 1 The code is 2836 bytes long starting at F400 finishing at FF14 with an entry point at F9A4 Should you require a hard copy listing of the source code a photocopy is available from MICRO 80 for 5 00 including postage A dump of the source code is included on both the monthly cassette and disk Line numbers mentioned in the remainder of these instructions refer to the source code The value of 100 loaded into register BC in line 1120 is to allow room for program expansion This may be altered to a larger value if required though expansion will only occur when processing a normal BASIC program extending variable names to two characters and or adding type flags The following is a brief description of how LONGVARS works After first finding out what you wish to do it scans the BASIC program in memory looking for variables Whenever it finds one it scans the table of variables it has already found or you have entered for a match If there is a match it adds the line number to its table and continues If there is no match it adds the name and the line number to its tables unless specified variables only are being handled During this phase a graphics character at the top of the screen will wiggle to indicate each new line scanned In the next
33. to make sure that there are no data reading errors N B With suitable changes to the input and print statements the above procedure would also allow the production of back up tape copies 8 The following changes must also be made to allow the programs to run under Disk BASIC a Type LOAD TTYPE1 BAS b Type 25 OPEN I 1 TTYPE3 TXT c Type 35 CLOSE d Modify lines 30 and 8f to look like the following 30 FORK T06000 NEXT CLS PRINT THIS COURSE RELIES HEAVILY ON THE USE OF STATEMENTS AND THE LOADING OF SUBROUTINES FROM DISK PLEASE LEAVE YOUR DISK INSERTED INPUT 1 D PRINTD 80 PRINT READY CHR 34 YOU SHOULD TYPE CHR 34 RUN CHR 34 AND PRESS ENTER YOU WILL THEN BE ASKED TO SELECT YOUR STARTING POINT 0 01000 NEXT CLEAR LOAD TTYPE2 BAS 1 e Type SAVE TTYPET BAS f Type LOAD TTYPE2 BAS g Type 75 OPEN I 1 TTYPE4 TXT Modify line 80 to look like 80 ONERRORGOTO89 INPUT 1 LL C TE IFLNCLLTHENCLS PRINT REWIND IT PLEASE GOSUB270 CLS 60 080 ELSEIFLL lt gt LNPRINT 256 READING LL GOTO8 i Type SAVE TTYPE2 BAS I also noticed an error in line 130 of my copy of TOUCHTYPE which resulted in the being omitted from the keyboard display The correct line 130 is shown below 130 CLS PRINT 384 STRING 64 131 1 2 34 3 4 5 6 amp 7 8 3 0 v Q W E OR T Y U I 0 P 68 CH 93 sCHR 92 5 A S D F G H J K 0000000000
34. two preceders Let us analyse the program In line 10 the two first numbers are put into A In line 30 A I is set to the sum of A I 1 and A I 2 and the result is printed in line 40 This is repeated several times line 20 and 50 ADVANCED PROGRAMMERS You often have to use several arrays within one program The solution to this is to divide A into many pieces Suppose you want to create three arrays one with 14 elements tne second with 10 elements and the tnird with 20 You want to print the F th element of each array This is written PRINT A F A 144F A 14 10 F Just remember to keep the index within the proper limits EXPERTS If you are in need of a 2 dimensional array also tnis can be done You have an array 10 5 i e having 10 rows and 5 columns and want to know the value of I J You then type PRINT A 5 I J By using the simple principles shown above you are able to create rather complicated structures You have an array 5 7 9 the elements from 0 to 20 in A are already used and you would like to put PI into I J K I suggest that you should express it this way LET A 20 9 7 I49 J K 3 1415926 You should always be careful with these arrays as they occupy large parts of your RAM This one ate 5 7 9 4 1260 bytes 000000000 TRANSFERRING TOUCHTYPE TO DISK by G F Hilder TOUCHTYPE is one of the more popular educational programs we have published on cassette It does take
35. us mmmmm Oodd o TMD F83 ooooo eo as oo op oo 45 17 F8 CD 7 C1 D6 02 c 2861 Auvmugid ON 08 LE 39Vd F860 F87 F88 mmmmmm CD CO CD CO C0 CD F90 2 5 555522 gt 5 gt 925 gt 535925925 gt 95555925 gt 5 gt 5 gt 525259299555292925 gt 92 gt 2 gt 9229295099999999 F93 77 9 2 F96 F97 TT T T 299932 OND F9D F9E gt lt 2n FAI FA2 FAS TD FAG FA7 TTT T 7T 7 7 7 7 MDDDDDDDD OTM DIDOM D OO 1 FR2 FBS mmmmmmm QU CD ng CU CO CD 52 4C a CD BD DF 9B 5B 23 5 45 ED 2 lt FE 6F 20 20 45 L 53 45 45 50 20 45 E 4D 53 52 58 20 59 41 44 53 20 44 oo 20 20 OD 4D a CD 1B 3A 56 45 E Ps o8 F DS o8 Di B7 52 4D 23 20 4F a 5 2 lt 41 45 20 a 45 20 49 2 4D oD 20 45 52 49 45 53 oD 45 20 E Ps 20 56 59 20 55 41 4F 1C EO 15 cD 99 72 cD ED 04 cD FC cD F3 32 54 MN UU ahh ooouoo 4C oo 20 56 ER C9 SF
36. word LET Although LET is almost never used it is available in BASIC However not all 80 interpreters run into this problem so there are obviously variations between machines Perhaps it would be wise for authors to avoid variable names which form the first two letters of a reserved word Ed 0000000000 READERS REQUESTS This column is a regular feature of MICRO 80 In it we list all those articles programs etc requested by our readers We invite contributions from readers to satisfy these requests and will of course pay a publication fee for all articles programs etc printed As a guide we will pay a minimum publication fee of 10 for any article or review published In the case of software reviews we will aim to pay in accordance with the value of the program up to a maximum of 25 So if you write a good review which we publish and the usual selling price of the program in Australia is 19 95 then we would pay you 20 In that way the successful reviewer will get the program he reviews free Make sure you include the selling price in your review Unfortunately we cannot afford that policy on hardware so we will pay in accordance with the merits of the review generally of the order of 25 Submission of a review for publication automatically means that you are prepared to accept the figure we decide to pay you and no correspondence will be entered into Payment will be made within 30 days of publication
37. you actually want to do when the BREAK key is pressed An obvious thing is to close disk files before exiting from the program Or perhaps you d want to allow only one pressing of BREAK in your program by disabling it in line 3270 after the first press then return to the program Or perhaps you will have given an instruction not to press the BREAK key and take some action if the operator does press the BREAK key after your instruction not to As usual with computing the possibilities are limited only by the imagination In fact all the routines presented in this series are intended only to provoke thought and to use in your own programs As I keep saying the way to learn and understand is to use these ideas for yourself SOUND The whole basis of the simple sound routine found in many programs is that to record onto tape the 80s PORT 255 is used to send positive or negative voltages to the cassette System 80s can use the second cassette by enabling bit 2 of PORT 254 which acts as a switch to change from the on board cassette so sound will still come down the AUX line to the second cassette All that is necessary is to put an instruction at the start of the program to OUT 254 4 and this will be effective throughout the whole program until you go back to BASIC and get the READY message again This also works in machine language programs so if you modify the many sound programs by adding machine language code for OUT 254 4 at the entry poin
38. 1B 55 56 4E 20 20 4R 26 CD 1E 2861 834 ON JWNTIOA 08 0XJIW 26 39Vd 10 THE MIND READER C COPYRIGHT 1980 BY PETER J SMITH C BOX 145 PENRITH N S W 2750 20 CLS PRINTTAB 20 T HE MIND READ E R PRINTTAB 20 STR 28 129 PRINT PRINTTAB G1 B Y PRINT PRINTTAB 23 P E TER SMIT 40 PRINT PRINT CHOOSE A LIST 1 2 3 4 5 6 50 PRINT PRINT THINK OF A NUMBER FROM 1 TO 63 DO NOT TELL ME WHAT IT IS MEMORIZE THE NUMBER AND ANSWER THE QUESTIONS BY PRESSING OR N tt 60 PRINT PRINT NOW WHICH LIST WOULD YOU PREFER 70 A INKEY IFA THEN7O ELSEA VAL A IF A lt 10RA gt 6 GOTO7O 90 CLS Y 1 N 2 100 ON A GOTO 110 210 310 410 110 GOSUB 950 GOSUB1560 120 PRINTTAB 23 LIST NO 1 130 GOSUR 1550 140 B INKEY IFB THEN140 150 IF BS Y THEN 180 510 610 160 U o 170 GOTO 190 180 U 1 190 CLS 200 IF 4 2 THEN 720 210 GOSUB 1050 GOSUB1560 220 PRINTTAB 23 LIST NO 2 230 1550 240 C INKEY IFC THEN240 250 IF C Y THEN 280 260 V 0 270 GOTO 290 280 V 2 290 CLS 500 IF A 3 THEN 720 310 GOSUB 1150 GOSUB1560 320 25 LIST NO 3 330 GOSUB1550 340 0 IFD THENS40 350 IF D Y THEN 380 360 W 0 570 GOTO 390 380 W 4 390 CLS 400 IF A 4 THEN 720 410 GOSUB 1250 GOSUB1560 420 PRINTTAB 23 LIST NO 4 430 GOSUR 1550 440 IFES THEN440
39. 92 80 track dual head drive stores 204 Kilobytes of formatted data on EACH side of a 5 inch diskette single density mode That s 408 Kilobytes per diskette In double density mode the B92 stores a mammoth 408 Kilobytes per side or 816 Kilobytes of formatted data per diskette With two B92 s and a PERCOM double you could have over 1 6 Megabytes of on line storage for your TRS 80 for less than 515001 MPI B91 80 Track Single Head Drive only 499 MPI B92 80 Track Dual Head Drive only 619 Prices are for bare drives and include p amp p Add 10 00 per drive for a cabinet and 60 00 for a power supply to suit two drives Note 80 track drives will not read diskettes written on a 35 or 40 track drive If drives with different track counts are to be operated on the same system NEWDOS 80 must be used CARE FOR YOUR DISK DRIVES THEN USE 3M s DISK DRIVE HEAD CLEANING DISKETTES 30 20 incl p amp p Disk drives are expensive and so are diskettes As with any magnetic recording device a disk drive works better and lasts longer if the head is cleaned regularly In the past the problem has been how do you clean the head without pulling the mechanism apart and run ning the risk of damaging delicate parts 3M s have come to our rescue with SCOTCH BRAND non abrasive head cleaning diskettes which thoroughly clean the head in seconds The cleaning action is less abrasive than an ordinary diskette and no residue is left behind
40. D BACK BY AN ANTIQUATED DISK OPERATING SYSTEM MOVE UPTO NEWDOS 80 149 incl p amp p NEWDOS 80 is a completely new DOS for the TRS 80 SYSTEM 80 It is well documented bug free and increases the power of your system many times over It is upward compatible with TRSDOS AND NEWDOS ie TRSDOS and NEWDOS programs will run on NEWDOS 80 but the reverse is not necessarily so These are just a few of the many new features offered by NEWDOS 80 New BASIC commands that support variable record lengths up to 4095 bytes long Mix or match disk drives Supports any track count from 18 to 96 Use 35 40 77 or 80 track 5 inch mini disk drives 8 inch disk drives OR ANY COM BINATION An optional security boot up for BASIC or machine code application programs User never sees DOS READY or READY and is unable to BREAK clear screen or issue any direct BASIC statements including LIST New editing commands that allow program lines to be deleted from one location and moved to another or to allow the duplication of a program line with the deletion of the original Enhanced and improved RENUMBER that allows relocation of subroutines Create powerful chain command files which will control the operation of your system Device handling for routing to display and printer simultaneously MINIDOS striking the D F and G keys simul taneously calls up a MINIDOS which allows you to perform many of the DOS comma
41. ELECTRONICS 212 KATOOMBA ST KATOOMBA N S W 2780 PHONE 047 82 2491 MICRO 80 LEVEL 2 ROM ASSEMBLY LANGUAGE TOOLKIT by Edwin Paay FOR TRS 80 MODEL 1 MODEL 3 AND SYSTEM 80 VIDEO GENIE This is anew package consisting of two invaluable components ROM REFERENCE Manual which catalogues describes and cross references the useful and usable ROM routines which you can incorporate into your own machine language or BASIC programs eDBUG a machine language disassembling debugging program to speed up the development of your own machine language programs DBUG is distributed on a cassette and may used from disk or cassette Part 1 of the ROM REFERENCE manual gives detailed explanations of the processes used for arithmetical calculations logical operations data movements etc It also describes the various for mats used for BASIC System and Editor Assembly tapes There is a special section devoted to those additional routines in the TRS 80 Model 3 ROM This is the first time this information has been made available anywhere Differences between the System 80 Video Genie are also described Part 1 is organised into subject specific tables so that you can quickly locate all the routines to carry out a given function and then choose the one which meets your requirements Part 2 gives detailed information about each of the routines in the order in which they appear in the ROM it describes their functions explains
42. END SA 5031 MICRO 80 433 Morphett Street Adealide SPECIAL OFFER TO NEW READERS AND READERS RENEWING THEIR SUBSCRIPTION SOFTWARE LIBRARY VALUED AT OVER 100 FREE MICRO 80 has developed a new Library of Software consisting of 7 programs and a comprehensive user manual The Software Library on cassette will be sent FREE to every new subscriber and to every subscriber who renews his sub scription for another 12 months Disk subscribers will receive their Software Library on a diskette The new Software Library contains the following Level II Disk Programs All programs will also operate on the Model III Level I in Level II Convert your Level II TRS 80 or System 80 to operate as a Level I machine Opens a whole new library of software for your use Copier Copies Level II System tapes irrespective of where they load in memory Copes with multiple ORG programs Z80 MON A low memory machine language monitor which enables you to set break points edit memory punch system tapes etc Cube An ingenious representation of the popular Rubick s cube game for Disk users Poker Play poker against your computer complete with realistic graphics Improved Household Accounts Version 3 0 of this useful program One or two bugs removed and easier data entry This program is powerful enough to be used by a small business 80 Composer A music generating program which enables you to play music via your cassette
43. Each kit contains 2 head cleaning diskettes 1 bottle of cleaning fluid 1 bottle dispenser cap PLEASE USE ORDER FORM ON PAGE 36 PAGE 18 USE TANDY baka ON YOUR SYSTEM 80 SYSPAND 80 97 50 incl p amp p The SYSTEM 80 hardware is not compatible with the TRS 80 in two important areas The printer port is addressed differently and the expansion bus is entirely different This means that SYSTEM 80 owners are denied the wealth of economical high performance peripherals which have been developed for the TRS 80 Until now that is MICRO 80 has developed the SYSPAND 80 adaptor to overcome this problem A completely self contained unit in a small cabinet which matches the colour scheme of your computer it con nects to the 50 way expansion part on the rear of your SYSTEM 80 and generates the FULL Tandy 40 way bus as well as providing a Centronics parallel printer port SYSPAND 80 enables you to run an Exatron Stringy Floppy from your SYSTEM 80 or an LNW Research expansion interface or any other desirable peripherals designed to interface to the TRS 80 expan sion port Make your SYSTEM 80 hardware compatible with the TRS 80 via SYSPAND 80 PROGRAMS BY MICROSOFT EDITOR ASSEMBLER PLUS L2 16K 37 50 1 20 p amp p A much improved editor assembler and debug monitor for L2 16K TRS 80 or SYSTEM 80 Assembles directly into memoty supports macros and conditional assem bly includes new commands substitute move cop
44. GE TOOKIT FOR ONLY 19 95 Send back your original Level ROM Reference Manual plus a cheque money order or Bankcard authorisation for 19 95 plus 2 00 p amp p and we will send you the new ASSEMBLY LANGUAGE TOOLKIT MICRO 80
45. M 4341 4C 00870 DEFM LLIST 4346 89 00700 DEFB DELIM 4347 43 00710 DEFM CSAVE 434C 80 00720 DEFB DELIM 434D 53 00730 DEFM SAVE 4351 80 00740 DEFB DELIM 4352 FF 00750 DEFB ENDMRK END OF TABLE MARKER eocc 00760 END BASIC This is the source code for the BASIC routine presented last time to disable BREAK LIST and others As you see from the comments any other commands may be added to the table as required The whole basis of the program is that it intercepts the keyboard scanning routine normally provided by the operating system This is accomplished by an address being given to 4 16 so that the operating system will go through this new routine each time it scans the keyboard instead of doing its own normal routine VOLUME 3 NO 3 FEBRUARY 1982 MICRO 80 PAGE 8 Having jumped into this new routine a ROM routine is used to get the value of any key pressed then to check it as noted in the comments If it s none of the new operators provided it just returns to the usual system But if it is it goes through the program and checks the keyboard buffer contents against the table provided Two items contained in this program you d be unlikely to know without Eddy Paay s ROM Reference Manual that 4 16 is the address to be used to set a new keyboard vector and a CALL to 3E3H will provide the results of a keyboard scan in the A register BREAK handling As mentioned in the first article there are some simple POKE methods fo
46. N FOR I U DOWNTO L DO TABLE I 1 TABLE I END BEGIN OF MAIN FOR I 2 TO N DO BEGIN IF TABLE I lt TABLE I 1 THEN BEGIN TEMP TABLE I BINARYSEARCH TABLE 1 1 1 BLOCKMOVE TABLE POSITION 1 1 TABLE POSITION TEMP END END END The corrections were made in the following In Procedure BINARYSEARCH IF LOW UPP THEN POS LOW instead of 1 because although the procedure was demonstrated as a search routine for a specific value it needed a modification to allow it to be used in the insertion sort for determining the correct position in sequence of a value that may not be currently in the table In the Main Procedure block The second parameter used in the BLOCKMOVE call U 1 should read POSITION because this is the parameter as returned from the CALL to the BINARYSEARCH procedure Same correction to the next line where TEMP is moved into that POSITION in the TABLE 0000000000 BETTER BASIC PROGRAMMING PART 7 by Rod Stevenson YET MORE ASSEMBLY WHY SO MUCH ASSEMBLY The emphasis on assembly in these last three articles is not merely that I find it gives far greater satisfaction than BASIC but that so much can be done in assembly whereas BASIC is limited to that which is provided by the writers of the BASIC interpreter in ROM Not to put down BASIC at all I still use it for most of the real programming I do From the previous two articles and with wh
47. RAMA L2 16K Cassette 10 95 Disk 15 95 60c p amp p Two programs which give fascinating ever changing patterns on the screen LIFE is the fastest implementation of the Game of Life you will see on your 80 Machine language routines create up to 1200 new generations per minute for small patterns or up to 100 per minute for the full 128 x 48 screen matrix Features full horizontal and vertical wraparound EPICYCLES will fascinate you for hours The ever changing ever moving patterns give a 3D effect and were inspired by the ancient Greek theories of Ptolemy and his model of the Solar system EDUCATION AND FUN L1 4K L2 16K Cassette 10 95 Disk 15 95 60c p amp p Written by a primary school teacher to make learning enjoy able for his pupils there are five programs in both Level and Level II to suit all systems BUG A LUG a mathematics game in which you must get the sum correct before you can move AUSTRALIAN GEOGRAPHY learn about Australian States and towns etc SUBTRACTION GAME build a tower with correct answers HOW GOOD IS YOUR MATHS Select the function or X and degree of difficulty HANGMAN That well known word game now on your computer Recommended for children from 6 to 9 years COSMIC FIGHTER amp SPACE JUNK L2 16K Cassette 10 95 Disk 15 95 60c p amp p Both programs have sound to complement their excellent graphics In COSMIC FIGHTER you must defend the earth against seve
48. STARTING WITH RESERVED WORDS ELSE ANY OTHER KEY Using the examples of STIFF and FORK the answer would be Y as FORK starts with a reserved word The next prompt from the program asks PRESS T TO SET ALL VARIABLES WITH TYPE DECLARATION FLAG ELSE PRESS ANY OTHER KEY THis will simply add a type flag to all variables A note of caution here if your lines already contain the maximum number of characters your program could be scrambled Always SAVE your program first The next prompt from the program is PRESS S TO ALLOW SINGLE LETTER NAMES ELSE ANY OTHER KEY If you type S then LONGVAR will replace all your variable names with single letter names i e A B C D E F G etc if you type any other key then LONGVAR will use double letter names i e AA BB CC DD EE FF GG etc The last question asked by this section of the program is PRESS V TO SET VIDEO OUTPUT ANY OTHER KEY FOR PRINTER Depending on your response the display will either go to the VDU or the printer After that question has been answered the program will start renaming your variables listing the original variable name the name it has been changed to and the line numbers where the changes were made E g VARIABLE STIFF RENAMED A IN LINE 70 80 90 105 VARIABLE FORK RENAMED TO B IN LINE 35 60 130 etc etc While the renaming is taking place a graphic dot at the top left of the screen will wiggle anytime that the program appears inactive so as to show tha
49. TRY 430D eesee BREAK LD A 1 BREAK 45 C9 eesie RET 4510 3E60 052 SHFTAT LD A 66H SHIFT 2 4312 C9 ee5 e RET 4313 D9 60540 CHKBUF EXX SAVE REGISTERS 4314 EDSBA44e ee55e LD DE 4 A4H 4318 AF 00540 XOR 4319 67 00570 LD H A 431A 2E53 eesse LD L TABLE START 8 431 19 00570 ADD HL DE 431D EB eecoe EX DE HL 431E 200740 61 LOOP1 LD HL BPOINT GET BUFFER ADDRESS 4321 2B 00620 DEC HL 4322 D7 RST 10H FIND FIRST CHARACTER 4323 1A LOOP LD A DE GET CHARACTER 4324 13 BUMP POINTER 4325 B7 OR 4326 FACC S 909570 JP M BASIC IF MINUS REINIT BASIC 4329 BE eecne HL COMPARE CHARACTERS 432A 23 HL BUMP POINTER 432B 28F6 99790 JR 2 1 GET NEXT CHARACTER 432D 1A ee71e LOOPS LD A DE 452 13 00720 INC DE 432F 00730 cP 80H FIND NEXT ENTRY 4331 2 00740 JR NZ LOOPS IN TABLE 4333 1A 00750 LD A DE 4334 FEFF 00760 cP ENDMRK END OF TABLE MARKER 4336 209E6 00770 JR NZ LOOP1 4338 D9 00780 EXX RESTORE REGISTERS 4339 3EOD 79 ENTER LD A ODH PUT ENTER CODE BACK IN A 433B C9 eenee RET DONE eesie 2 THE TABLE THAT FOLLOWS MAY HAVE AS MANY ENTRIES AS e830 REQUIRED AS LONG AS ENTRIES ARE SEPARATED WITH A ZERO C0846 BYTE THE MAIN PROGRAM WILL MAKE BASIC IGNORE ANY e850 COMMAND CONTAINED IN THIS TABLE 3 433C AC 0870 TABLE DEFM LIST 454 80 DEFB DELI
50. VEC EQU 4016H 40B1 00230 TOPMEM EQU 40B1H 0250 00240 DELAY EQU 0250H 40A0 00250 SPOINT EQU 40A0H 1B6E 00260 SETPTR EQU 1 B6EH 0020 00270 SPACE EQU 0020H 00280 VIDEO EQU 3COOH 00290 00300 INITIALIZE 00310 7EES 00320 INIT DI 7EE6 210C7F 00330 LD HL START 7EE9 221640 00340 LD KBVEC HL 7EEC 2B 00350 DEC HL 7EED 2B 00360 DEC HL 7EEE 22B140 00370 LD TOPMEM HL MEMORY SIZE 7EF1 113200 00580 LD DE 32H 7EF4 B7 00390 OR A 7 5 EDS2 00400 SBC HL DE 7EF7 22A040 00410 LD SPOINT HL 00420 00430 SET LOAD AND KILL COMMAND VECTORS 00440 7EFA 21E57E 00450 LD HL INIT 7EFD 228941 00460 LD 4189H HL 7FOO 21F67F 00470 LD HL KILL 7FO3 229241 00480 LD 4192H HL 7FO6 CD6E1B 00490 CALL SETPTR ALL OTHER POINTERS 7FO9 C3CCO amp 00500 JP BASIC 00510 00520 MAIN ROUTINE 00530 7FOC SAF57F 00540 START LD A TEST TEST FOR PROGRAM RUNNING 7FOF B7 00550 OR 7F10 2004 00560 JR NZ CONT 7F12 D9 00570 EXX 7F13 CD2C7F 00580 CALL PRINT PRINT MESSAGE 7F16 CDESO3 00590 CONT CALL KBSCAN 7F19 D9 00600 7F1A B7 00610 OR A 7F1B 2046 00620 JR NZ RESCNT 7F1D 2AF37F 00430 LD HL COUNT 7F20 7C 00640 LD A H 7F21 B5 00650 OR L 7F22 00660 LD 0 0 7F24 2806 00670 JR Z PRINT 7F26 2B 00680 DEC HL DECREMENT COUNTER 7F27 22F37F 00690 LD COUNT HL 7F2A D9 00700 7F2B C9 00710 RET VOLUME 3 NO 3 FEBRUARY 1982 MICRO 80 PAGE 30 00720 00730 THIS FLASHES MESSAGE 00740
51. W NEW MODEL 500 5 MEGABYTE MODEL 5 1 40 TRACK DUAL HEAD DRIVE GIVING 350K OF FLOPPY DISK STORAGE FOR TRANSFERRING PROGRAMS AND BACKUP 48K RAM EXTERNAL 5 MEGABYTE WINCHESTER SUB SYSTEM CP M ORG 4200N DISK OPERATING SYSTEM 5895 The MODEL 500 offers the high speed mass storage capacity and reliability of a Winchester drive for thousands of dollars less than you would pay for any comparable system Model 500 is a serious business computer able to tackle the most demanding tasks All prices are in Australian dollars include Sales Tax and are subject to change without notice Prices are FOB Adelaide Add 20 road freight anywhere in Australia All computers and systems carry MICRO 80 s 90 day Warranty covering parts and labour SAVE A PACKET ON MICRO 80 s DISK DRIVE PACKAGES FOR TRS 80 MODEL 1 AND SYSTEM 80 MICROCOMPUTERS SINGLE DRIVE PACKAGE from 499 DUAL DRIVE PACKAGE from 874 Bigger volume means lower cost price which we are passing on to you Avoid the annoying bundle of cables wires and separate boxes MICRO 80 is now offering our well proven MPI disk drives in attractive self contained single or dual drive cabinets complete with internal power supply Our drive 0 and dual drive packages also in clude the appropriate version of DOSPLUS and dual drive cable The best news of all is the specially reduced package prices SAVE 25 107 over our already low prices Choose the appropriate system from th
52. YSTEM 80 S KEY allows text BASIC commands and or graphics to be defined to shifted keys This makes programming much easier as whole commands and statements can be recalled by typing shift and a letter key Because S KEY allows graphics to be typed directly from the keyboard animation and fast graphics are easily implemented by typing the appropriate graphics symbols directly into PRINT statements S KEY allows the user to LIST a program with PRINT statements containing graphics properly S KEY does this by intercepting the LIST routine when necessary S KEY allows the user to list an updated list of the shift key entries to the video display or line printer S KEY can be disabled and enabled when required This allows other routines which take control of the keyboard to run with S KEY as well Each cassette has TRS 80 DISK and SYSTEM 80 versions and comes with comprehensive documentation BMON by Edwin Paay 19 95 plus 50c p amp p THE ULTIMATE HIGH MEMORY BASIC MONITOR L2 16 48K Our own personnel refuse to write BASIC without first loading this amazing machine language utility program into high memory BMON Renumbers Displays BASIC programs on the screen while they are still loading tells you the memory locations of the program just loaded lets you stop a load part way through merges two programs with automatic renumbering of the second so as to prevent any clashes of line numbers recovers your program even though you did
53. al period So confident are we of the system that we will refund the full purchase prices less the cost of freight in either direction if a sub system is returned to us in original condition within 30 days of purchase We are proud to be involved in bringing this new development to TRS 80 users in Australia Now read on to find out more about the 80 hard disk sub system VOLUME 3 NO 3 FEBRUARY 1982 MICRO 80 PAGE 3 The sub system consists of the following components 5 Mbyte 54 seagate ST 506 or similar micro winchester hard disk drive ACT 506 microsequencer controller board HOP high integrity data separator interface card for host computer heavy duty power supply free standing moulded plastic cabinet CP M disk operating system and utilities for host computer The controller board itself contains in excess of 60 integrated circuits and is capable of con trolling two 5 Mbyte micro winchester hard disk drives simultaneously The micro winchester can read data at a burst rate of 5 million bits per second The controller accepts data at this rate and stores it until the host computer has transferred it via the interface card The form of construction used allows the sub system to be transferred to a different computer at minimal cost since only the host computer interface card and the CP M need be changed The CP M disk operating system supplied has a number of enhancements and is specially tailored to sui
54. at follows here I hope you will share my enthusiasm for assembly not only for the speed and because it s the only way to modify the operating system but for the self satisfaction in having got a job done efficiently LIST DISABLE 00100 00110 TO DISABLE SHIFT 3 CSAVE BREAK LIST SAVE LLIST 00120 DISABLED COMMANDS MAY BE ALTERED IN TABLE FROM LINE 870 00130 00140 BY E R PAAY 00150 FOR R STEVENSON 00160 24 8 1980 00170 00180 NOTE SHIFT A SHIFT 3 SHIFT B BREAK 00190 AFTER THIS PROGRAM IS LOADED 00200 4016 00210 ORG 4016H 4016 F142 00220 DEFW START SET NEW KB VECTR 42F1 00230 ORG 42F1H 00240 00250 DEFINE LABELS 00260 4047 00270 BPOINT EQU 40A7H 00280 BASIC EQU 0080 00290 DELIM EQU 80H VOLUME 3 NO 3 FEBRUARY 1982 MICRO 80 PAGE 7 OOFF eesee ENDMRK EQU OFFH KBSCAN EQU 3E3H START OF PROGRAM 42F1 CDE3 3 35 START CALL KBSCAN SCAN KEYBOARD 42F4 FE65 eesoe cP 65H SHIFT E A2F6 2841 00370 JR Z ENTER 42F8 FE62 00380 cP 62H SHIFT B 42FA 2811 00370 JR Z BREAK 42FC FE61 61H SHIFT 42FE 2810 1 JR Z SHFTAT 4300 FEOD 00420 cP ODH ENTER 4302 280F Z CHKBUF 4304 FE 1 BREAK 4306 2803 JR Z IGNORE 4308 00440 cP SHIFT 3 4364 00470 RET NZ 43eB AF ee48e IGNORE XOR 45 C9 00470 RET IGNORE KEY EN
55. ddress expected data and actual data are printed out together with a detailed error analysis showing the failing bit or bits the corres ponding IC s and their location This is the most thorough test routine available for TRS 80 disk users BOOKS LEVEL II ROM REFERENCE MANUAL 24 95 1 20 p amp p Over 70 pages packed full of useful information and sample programs Applies to both TRS 80 and SYSTEM 80 TRS 80 DISK AND OTHER MYSTERIES 24 95 1 20 p amp p The hottest selling TRS 80 book in the U S A Disk file structures revealed DOS s compared and explained how to recover lost files how to rebuild crashed directories this is a must for the serious Disk user and is a perfect companion to any of the NEWDOS s LEARNING LEVEL II 16 95 1 20 p amp p Written by Daniel Lien the author of the TRS 80 Level Handbook this book teaches you step by step how to get the most from your Level II machine Invaluable supplement to either the TRS 80 Level II Manual or the System 80 Manuals MORE AUSTRALIAN SOFTWARE programs designed to run on both the T RS 80 or the SYSTEM 80 without modification Most programs include sound TRIAD VOL 1 L2 16K Cassette 10 95 Disk 15 95 60c p amp p Three separate games which test your powers of memory and concentration The programs combine graphic displays and sound SIMON SEZ Just like the electronic music puzzles on sale for more than 20 Numbers are flashed on the sc
56. duplicates in the list are allowed Also the list insertion sort does not do any deletion operations Now that the essential list processing algorithms have been coded the rest of the list insertion sort and driver follow 1850 0 2 0 INITIALIZE HEAD 1900 FOR AD 1TON 1950 605081550 LINK ITEM STRUCTURE 2000 NEXT AD 2050 RETURN 2100 MAIN DRIVER 2200 A LINKED LIST STRUCTURE AS SIMULATED BY THE ARRAY 2250 PRED ADDRESS OF PREDECESSOR NODE 2300 FOUND FLAG SET TRUE WHEN INSERTION POSITION FOUND 2350 PNTR TEMPORARY POINTER VARIABLE 2355 AD ADDRESS OF CURRENT ITEM UNDER CONSIDERATION 2360 A AD 1 VALUE OF NEW ITEM TO BE INSERTED 2380 DEFINTA Z 2400 CLS INPUT NUMBER OF ITEMS FOR SORTING N IFNX amp ITHEN2400 2450 DIMA N 2 TRUE 1 FALSE 0 RANDOM 2500 PRINT LIST BEFORE SORT 2550 FORI 1TON 2600 A I 1 RND 1000 A 1 2 0 PRINTA I 1 2650 NEXT 2700 PRINT INPUT HIT ENTER TO START SORT I 2750 GOSUB1850 2800 PRINT LIST AFTER SORT 2850 PNTR A 0 2 2900 IF PNTR 0 THEN 3050 2950 PRINTA PNTR 1 PNTR A PNTR 2 3000 60702900 2050 END SOME POINTS OF EXPLANATION The initial unsorted data is placed in a 2 dimensional table rather than a one dimensional array because this is the structure needed to simulate the linked list The head of the linked list is located in row zero with the point value in column 2 The value of the null pointer is zero since an address of zero is not valid for an item be
57. e table below No of No of Dosplus DRIVE Tracks Heads Capacity Version Price Saving DRIVE 1 x MPI B51 40 1 100K 3 3 499 77 95 1 x MPI B52 40 2 200K 3 4 639 97 95 1 x MPI B92 80 2 400K 3 4 799 107 95 DRIVE 1 1 x MPI B51 40 1 100K 415 23 00 1 x MPI B52 40 2 200K 525 23 00 1 x MPI B92 80 2 400K 695 23 00 Represents the saving compared with buying all the items included in the package separately Drive package includes one bare disk drive self contained single Drive 1 package includes one bare disk drive and self contained drive cabinet power supply as illustrated two drive cable and the ver single drive cabinet power supply as illustrated sion of DOSPLUS indicated If it s a dual drive system you need then take advantage of our dual drive package and SAVE a further 40 on the price of two single drive packages No of No of Tracks Heads 2 x MPI B51 40 ea ea 2 x 100K 35 5 874 2 x MPI B52 40 ea 2 ea 2 x 200K 5 4 1125 2 x MPI B92 80 ea 2 ea 2 x 400K 3 4 1454 Dual drive package includes two bare disk drives self contained dual NOTE All 40 track drives are completely compatible with 35 track drive cabinet power supply as illustrated two drive cables and the operating systems such as TRSDOS DOSPLUS allows you to realise an version of Dosplus indicated additional 14 capacity compared with TRSDOS Under DOSPLUS 3 4 80 track drives can read 35 40 track diske
58. electronic technician to instal them DISK DRIVE CABLES SUITABLE FOR ANY DISK DRIVES DC 2 2 Drive Connector Cable 39 incl p amp p DC 4 4 Drive Connector Cable 49 incl p amp p DOUBLE THE SPEED AND CAPACITY OF YOUR DISK DRIVES PERCOM DOUBLER ONLY 220 plus 2 00 p amp p Installing a Doubler is like buying another set of disk drives only much cheaper The doubler works with most modern disk drives including MPI Micropolis Pertec TEAC as supplied by Tandy The doubler installs in the TRS 80 expansion interface the System 80 expansion interface and the LNW Research expan sion interface in a few minutes without any soldering cutting of tracks etc It comes complete with its own TRSDOS compatible double density operating system FOR NEWDOS 80 53 00 plus 1 00 p amp p DOS 80 then you also need ette This program upgrades at the same write to drive in single density wh time it reads writes to drive 1 in double dertsity FLOPPY DOCTOR AND MEMORY DIAGNOSTIC by MICRO CLINIC 29 95 plus 50c p amp p Two machine language programs on a diskette together with manual which thoroughly test your disk drives and memory There are 19 possible error messages in the disk drive test and their likely causes are explained in the manual Each pass of the memory tests checks every address in RAM 520 times including the space normally occupied by the diagnostic program itself When an error occurs the a
59. en down payments made on new cars all from this windfall income This made the annual preparation of the Income Tax Return a tedious but rewarding exercise Then suddenly it all changed The Government adjusted tne PAYE rates so that tney very nearly collected the exact amount of money due during the year and refunds became negligible in size By now our overseas readers will be making plans to move to Australia where we obviously have a uniquely honourable Government which is prepared to forego the interest free use of hundreds of millions of dollars of its citizens money just to ensure that they are treated fairly VOLUME 3 NO 3 FEBRUARY 1982 MICRO 80 PAGE 28 Well unpack your bags the reason they did it was that it became fashionable for Governments to control the economy via the money supply and if you release hundreds of millions of dollars into the economy just when you are trying to hold things bacx you no longer have control To Governments of course control is far more important even than money hence the money went All that is now left for Australia s taxpaying citizens then is the annual tedium of completing their Income Tax Returns with little hope of reward This program will reduce that tedium a little by assisting you to calculate just how much refund you should get or how much extra you will need to render unto Caesar Overseas readers may find it interesting to compare their own rates of direct taxation with Australia
60. ering then 21 OC etc Locations 7F71H to 7FBOH must be filled with the HEX equivalent of the ASCII characters to be used in your message e g in the example given the first character is whose ASCII code in HEX is 3D 61 in decimal The first character must not be a space or 20H and all of the locations should be filled so that one complete line is printed Locations 7FB2H to 7FFIH must all be filled with 20H s so that the previous message is wiped out If all goes well you should finish at location 7 after typing in OSH Punch out a tape with the following parameters START 7EE5H END 7FFEH ENTRY 7EE5H NAME MESAGE The message is embedded in the machine code from address 7F71H to 7FBOH To change the message it would normally be necessary to alter the source code and reassemble If you include the following lines of BASIC code in your own BASIC program then you may change the message at will You may even change the message which flashes at different stages of your program and shift it around the screen using the POKES shown in Line 320 100 X THIS IS THE MESSAGE YOU WANT TO FLASH MUST BE 64 CHARACTERS LONG PAD WITH SPACES IF NECESSARY 116 FOR TO 63 129 POKE 32625 X ASC MID X 1 1 136 NEXT X 14 REM THE FOLLOWING CODE WILL ALLOW YOU TO SELECT THE LINE ON THE SCREEN IN WH ICH YOUR MESSAGE WILL BE DISPLAYED 156 INPUT LINE NO REQUIRED 1 16 LN IF LN lt 1 OR gt 16 THEN 15e 166 ADDRESS LN
61. ette Level i programs are recorded on side 2 Level I programs are not compatible with the System 80 All programs are recorded twice in succession Note System 80 computers have had different tape counters fitted at different times The approximate start positions shown are correct for the very early System 80 without the volume control or level meter They are probably incorrect for later machines The rates for a cassette subscription are printed on the inside front cover of each issue of the magazine The disk edition contains all those programs which can be executed from disk including Level I programs Level I disk programs are saved in the NEWDOS format Users require the Level I CMD utility supplied with NEWDOS or NEWDOS 80 version 1 0 to run them APPROX START POSITION TYPE I D DISK FILESPEC CTR 41 CTR 80 SYSTEM 80 SIDE 1 LONGVAR SYSTEM LONGVR LONGVAR CMD 15 10 11 u n 46 31 33 LONGVAR EDTASM LONGVR LONGVAR EDT 74 50 52 FLASHING MESSAGE SYSTEM MESSAGE CMD 240 162 170 amp 246 166 174 FLASHING MESSAGE EDTASM MESAGE MESSAGE EDT 252 170 178 x 275 186 195 FLASHING MESSAGE L2 16K M MESSAGE BAS 300 202 211 S 305 206 216 SIDE 2 INCOME TAX L2 4K T TAX BAS 15 10 11 n i 36 24 25 MIND READER L2 4K M MINDREAD BAS 55 37 39 92 62 65 VDU SAVE L2 16K VDUSAVE BAS 126 85 89 y 133 90 94 LONGVAR EDTASM LONGVAR LONGVAR EDT 140 95 100
62. h means that the print head will commence printing the next line from the end which requires the least travel thereby minimising unutilised time gives this printer a much higher throughput rate than many other printers quoting print speeds of 120 c p s or even higher GREEN SCREEN SIMULATOR 9 50 incl p amp p The GREEN SCREEN SIMULATOR is made from a deep green perspex cut to fit your monitor It improves contrast and is much more restful to the eyes than the normal grey and white image All editorial staff of MICRO 80 are now using GREEN SCREEN SIMULATORS on their own monitors Please make sure to specify whether you have an old squarish or new rounded style monitor when order ing Not available for Dick Smith monitors VOLUME 3 NO 3 FEBRUARY 1982 MICRO 80 PAGE 21 HOW TO USE THE TRS 80 LEVEL I ARRAY EFFECTIVELY Otto Reberg BEGINNERS The level I array is very unusual It has only one dimension and is automatically DIM med to MEM ory 4 1 Divide by 4 because each element occupies 4 bytes and subtract 1 byte which separates program and array The following example shows an easy way to use the array 10 LET 1 0 LET A 2 1 20 FOR I 3 TO 20 30 LET 1 1 2 40 PRINT A I 50 NEXT I This program generates and prints the number sequence of Fibonnachi in which the two first numbers are 0 and 1 and each of the following numbers are the sum of the
63. he insertion sorts so far that of item element or key movement Straight and multiple insertion required movement of individual items as they were ranked Binary insertion required movement of items as a logical block when the insertion position was found This is a necessary evil when dealing with insertions deletions in a sequential data structual such as the straight array To avoid this type of movement and still retain necessary ordering of items a non sequential data structure could be used that of linked organization commonly found in linked linear lists VOLUME 3 NO 3 FEBRUARY 1982 MICRO 80 PAGE 11 LINKED LIST ORGANIZATION AND PROCESSING In order to understand its use in the insertion sort the list insertion sort a brief explan ation of linked linear lists is offered Elements of any kind that are logically adjacent as items in a sorting array need not be physically adjacent as the physically adjacent cells in an array These elements known as nodes are logically linked by pointers The first logical node in a linked list is defined by a special variable known as the head of the linked list which is itself a special node The last element is denoted as such by the use of a special null value in its pointer field Figure 1 illustrates the logical representation of such a data structure NODE FIGURE 1 General structure of a singly linked list However unlike standard Pascal and some other program
64. hen changing the relationship between two items The general operations of insertion and deletion are formally defined in the flowcharts in figure 2 An important assumption here is that the head of the list is located at row zero in the tabte Some programming languages do not allow element zero addressing If the head is located in some other pointer variable then the special cases of insertion of a node in an empty list head contains null or insertion in the first position in the list must be considered as does deletion VOLUME 3 NO 3 FEBRUARY 1982 MICRO 80 PAGE 12 DUPLICATE if not allowed POINTER TO SET PREDECESSOR POS FOUND Y FIGURE 2 General processing algorithms singly linked linear lists Note Pntr is an abbreviation for POINTER VOLUME 3 NO 3 FEBRUARY 1982 MICRO 80 PAGE 13 APPLYING THE NEW DATA STRUCTURE In order to demonstrate the increased efficiency that this data structure can give to the insertion sort some of the list processing algorithms in the flowchart need to be coded 1195 60702100 Needed to route initial processing to driver 1200 Search 1250 PNTR A 0 2 PRED 0 FOUND FALSE SAME FALSE 1300 IF PNTR 0 OR FOUND THEN RETURN 1350 IF A PNTR 1 lt A AD 1 PRED PNTR PNTR A PNTR 2 ELSE FOUND TRUE 1450 60701300 1500 1550 605081250 1600 A AD 2 A PRED 2 1650 A PRED 2 AD 1700 RETURN INSERT The flag SAME in the flowchart is not required here because insertions of
65. hership for high seas reprovisioning and even has emergency radio for that terrible moment when the depth charges put your crew at risk Requires Level 11 16K SPACE INVADERS WITH SOUND 8 95 60c p amp p Much improved version of this arcade favourite with redesigned laser and cannon blasts high speed cannon 50 roving drone targets 10 motherships and heaps of fun for all Level II with and 16K versions on this cassette GOLF L2 16K 8 95 60c p amp p Pit your skills of mini golf against the computer Choose the level of difficulty the number of holes and whether you want to play straight mini golf or crazy golf Com plete with hazards water traps bunkers and trees Great fun for kids of all ages DOMINOES L2 16K 8 95 60c p amp p Pit your skill at dominoes against the computer which provides a tireless opponent Another application of supergraphics from the stable of Charlie Bartlett Dominoes are shown approximately life size in full detail except for colour The monitor screen is a window which you can move from one end of the string of dominoes to the other Best of all you don t lose any pieces between games KID S STUFF formerly MMM 1 8 95 60c p amp p Three games on one cassette from that master of TRS 80 graphics Charlie Bartlett Includes INDY 500 an exciting road race that gets faster and faster the longer you play SUBHUNT in which your warship blows up unfortunate little submarines all over the
66. how to use them in your own machine language programs and notes the effect of each on the various Z80 registers Part 2 also details the contents of system RAM and shows you how to intercept BASIC routines With this knowledge you can add your own commands to BASIC for instance or position BASIC programs in high memory the only restriction is your own imagination The Appendices contain sample programmes which show you how you can use the ROM routines to speed up your machine language programs and reduce the amount of code you need to write DBUG Eddy Paay was not satisfied with any of the commercially available debugging programs so he developed his own DBUG allows you to single step through your prodram has a disassembler which disassembles the next instruction before executing it or allows you to bypass execution and pass on through the program disassembling as you go displays edits memory in Hex or ASCII allows Register editing has the ability to read and write System tapes and all this on the bottom 3 lines of your screen thus freeing the rest of the screen for program displays Four ver sions of DBUG are included in the package to cope with different memory sizes The best news of all is the price The complete Level 2 ROM ASSEMBLY LANGUAGE TOOLKIT only Aus 29 95 2 00 p amp p UK 18 00 1 00 p amp p SPECIAL OFFER TO OWNERS OF THE LEVEL Il ROM REFERENCE MANUAL UPGRADE TO THIS ASSEMBLY LANGUA
67. ing sorted The method of displaying the results of the sort is not simply a sequential list of column 1 of the table since no actual shifting of items occurred they are still in the same physical sequence as before the sort Rather the results are extracted logically by following the logical relationship of the items as established by the link information of the pointers In short this method of insertion sorting obviates the necessity of moving a potentially large number of items down to vacate a position for insertion of a new item Instead insertion of a new item is achieved by modifying the link information inherent in the data structure YET ANOTHER VARIATION There is another variation of the insertion sort that has become popular known as the Shell sort or diminishing increment sort developed by Donald Shell in 1959 and documented in the VOLUME 3 NO 3 FEBRUARY 1982 MICRO 80 PAGE 14 A C M Collected Algorithms Algorithm 201 This algorithm is similar to the straight insertion sort except that instead of comparing adjacent items comparisons are made on items that are separated by an increment that diminishes with each pass One version of this algorithm appeared in Tandy Newsletter Volume No 9 May June 1980 and is reproduced below with modified driver and variable names A variation to this method of rearranging items in line 4180 when an out of sequence situation has been detected is known as Hibbard s modification
68. ion is identical to the standard CP M sysgen generation program described in the CP M manual FORMAT ASM Diskette initialization program for floppy drives FORMAT COM to initialize the hard disk run DISKTEST Test 9 BOOTHD ASM This is the bootstrap program used to read in and execute the boot BOOTHD COM sector from the hard disk The same program may be loaded into a user supplied EPROM to be used for automatic hard disk boot on CPU power up BIOS ASM This file supplied in source form only is the source for the BIOS supplied with the TRS 80 Model III System VOLUME 3 NO 3 FEBRUARY 1982 MICRO 80 PAGE 4 HARDBOOT ASM This is the program loaded from the boot sector of the hard disk HARDBOOT COM which will read the CP M operating system and the BIOS into memory and execute DISKTEST ASM Program to perform comprehensive testing of the 5MB disk sub DISKTEST COM system DEFDISK ASM Program to set the hard disk drive characteristics DEFDISK COM FIXDISK COM Program to locate and make invisible bad areas on the disk This program works on any disk run under CP M 2 2 TRSCPM Program allows copying from TRSDOS diskettes to CPM disks INSERTLF Program allow automatic insertion of line feeds after carriage returns in basic programs TIMEDATE Program allows setting of time and date for real clock usage CLOCKON Turn on display of time and date on CRT screen CLOCKOFF Turn off display of time and date on CRT screen SAVEFILE
69. is we make use of the ON ERROR GO TO function Incidentally I don t favour general use of this function as I believe your program should be fully debugged before you let it go I cannot agree with Rod in this There is nothing more annoying in an applications program if through gross operator error the program crashes for the user to see an error message generated by the BASIC interpreter such as OV error or 0M error Far better for the program to resume control and instruct the operator what to do next Ed To explain the program Line 10 tells the ON ERROR routine where to GO TO Line 20 puts the entry point of ID ERROR routine into the BREAK handling routine in the operating system Lines 26 27 32719 are just added in this example to show that the routine will handle otherwise occurring errors too though as I wouldn t expect your program to have any these lines would of course be unnecessary Lines 39 and 3270 are the real bones of the program and allow for continued pressing of BREAK as a demonstration VOLUME 3 NO 3 FEBRUARY 1982 MICRO 80 PAGE 9 Of course this is just an example routine Your real program would have only lines 10 20 32700 as well as the whole of its real working code And these line numbers are such for this very reason lines and 20 are necessary right at the start of the program to tell it where to go to Line 32700 would be replaced by a subroutine at the end of your program to do what
70. l Home 047 51 3221 MEETINGS 1st Friday of the month at 7 30 p m in Springwood Civic Centre NORTHERN TERRITORY DARWIN GROUP Contact Tony Domigan P O Box 39086 WINNELLIE 5789 QUEENSLAND BRISBANE GROUP SOUTH AUSTRALIA ADELAIDE GROUP Contact Rod Stevenson 36 Sturt Street Adelaide SA 5000 Tel 515241 between 9 4 VICTORIA EASTERN SUBURBS GROUP Contact Mr John Fletcher Tel Home 03 737 9544 Bus 03 89 0677 9 4 MEETINGS 4th Wednesday of the month at 7 p m at Kingswood College 355 Station Street Box Hill MICOM 80 USERS GROUP Contact Len Sanders Tel 03 560 8132 MEETINGS 1st Wednesday of each month at Alvie Hall High Street Mt Waverley NORTHERN AND WESTERN SUBURBS Contact Mr David Coupe Tel 03 370 9590 HEETINGS C P M Data Systems 284 Union Road Moonee Ponds Alternate Thursdays at 7 PENINSULAR GROUP Contact M G Thompson 03 772 2674 MEETINGS 2nd Tuesday of the month except January at State College Frankston GEELONG COMPUTER CLUB Contact The Geelong Computer Club P 0 Box 6 Geelong Vic 3220 MEETINGS 2nd Thursday of the month at Tybar Engineering Hampton Street Newton WESTERN AUSTRALIA PERTH 80 USERS GROUP Contact Lance Lawes Tel Home 07 396 2998 Contact Powell 09 457 6849 Bus 07 268 1191 Ext 15 MEETINGS 1st Tuesday of each month at 7 30 MEETINGS 15 Sunday each month at 2 p m at 21
71. ming languages BASIC does not support such dynamic linked structures so arrays are used to simulate them You may feel that to do so would be no better than the use of arrays in the straight insertion and binary insertion sort However this is not so as is demonstrated below To change the relationship of one item to another at least one item and usually many items needed physical movement in a sequential data structure To change the relationship of one item to another in a linked data structure a maximum of only two pointers needs to be moved and no actual item data movements need occur For example in a sequential structure insertion of an item at the third position of the structure requires the movement down of all items from the third position to the last In a linked structure insertion at the third position requires only the following Pointer of second item moved to pointer of new Address of new item moved to pointer of second item When inserting or deleting nodes from a linked structure the address of the predecessor node to the candidate node for the operation is required This is obtained by chaining through the structure following the pointers Now this is much more efficient than the movement of masses of items in a sequential structure especially if the number of items in a sort array is large In fact in a linked structure after the predecessor node is located the number of items in the sort array is irrelevant w
72. n Tank game for a single player HARDWARE Interfacing the 80 to external hardware Review on the performance of line filters Real Time clock Radio Teletype Morse interfacing RFI Radio Frequency Interference suppression Interface for a Teletype printer Fast tape storage A cheap add on keypad High speed card readers interfacing and documentation for the Model II 1 NOTE An denotes that we already have some suitable material on hand for this topic 0000000000 kkkkk M I CROBUGS KKKKK Vol 3 Issue 2 Page 1l The Theory and Techniques of Sorting Part 3 There were some errors the PASCAL Code used to illustrate A RECURSIVE APPROACH The corrected code for the procedure INSERTSORT is as follows MAIN PROGRAM BLOCK DECLARATIONS TYPE LIST ARRAY 1 N OF REAL VAR TABLE LIST L U POSITION INTEGER VALUE REAL PROCEDURE INSERTSORT VAR TABLE LIST FIRST LAST INTEGER VAR I INTEGER TEMP REAL PROCEDURE BINARYSEARCH VAR TABLE LIST LOW UPP INTEGER VALUE REAL VAR POS INTEGER VAR MID INTEGER BEGIN IF LOW UPP THEN POS LOW ELSE BEGIN MID LOW UPP DIV 2 IF VALUE lt TABLE MID THEN BINARYSEARCH TABLE LOW MID 1 VALUE POS ELSE IF VALUE gt TABLE MID THEN BINARYSEARCH TABLE MID 1 UPP VALUE POS ELSE POS MID END END VOLUME 3 NO 3 FEBRUARY 1982 MICRO 80 PAGE 6 PROCEDURE BLOCKMOVE VAR TABLE LIST L U INTEGER VAR I INTEGER BEGI
73. n all but very small programs LONGVARS overcomes these limitations You may use whatever names you wish such as BECOS includes a reserved word and AARDVARK and AARDVOLF to represent different variables and COUNT OF WORDS includes blanks The only restriction is that variable names starting with a reserved word must be followed by a type flag or 2 When you have written your program and it is in memory and a spare copy saved load and run LONGVARS It will process your program systematically altering all variable names sa that different variables have different one or two letter names Variable types are preserved However all statements defining variable types must occur in the program before any variable is used and it is preferable to type CLEAR ENTER before running LONGVARS to reset the variable type table to the default value of single precision LONGVARS may also be used to change the names of specified variables only or to produce a cross reference of all variables or specified variables only in a program It has an option of adding type flags to all variables and another option of not using single letter variable names always using double letter names may reduce variable access time by up to 52 The program produces its listing on either printer or video Video output may be halted by pressing any key and restarted by pressing a different key The source code runs to over 20 pages so is unfortunately too
74. n be used for all sizes of loaders in all types of conditions If you are in the earthmoving or mining business this should be very useful RESTORE LII 16K On some personal computers the EXIDY SORCERER to name one it is possible to include in the program a statement such as RESTORE 300 This then sets the data pointer to look at line 300 when the program encounters a READ statement instead of having to read in all the data in the program a great time saver Next month you too will have this function on your computer ALIEN INVASION 111 16 In this game you have to fight off the invading aliens If you let five of them land the game moves on into a second section which is even harder with lots of aliens all fighting back WANTED ARTICLES AND PROGRAMS FOR THE TRS 80 COLOUR COMPUTER AND THE HITACHI PEACH Starting with Vol 3 Issue No 5 MICRO 80 will be supporting the TRS 80 Colour Computer and the Hitachi Peach similar Microsoft BASIC interpreters of program ideas is past issues of MICRO 80 some of those we have published for the Models 1 and 3 with the added features of sound and colour Naturally we will Both these computers have a 6809 micro processor and use We require articles and programs which will be of interest to the users of these computers for publication One good source Why not write programs similar to pay a publication fee to each author So don t delay use the coupon bel
75. n different types of alien aircraft It is unlikely that you will be successful but you will have a lot of fun trying You mission in SPACE JUNK is to clean up all the debris left floating around in space by those other space games It is not as simple as it sounds and space junk can be quite dangerous unless you are very careful SPACE DRIVE L2 4K amp 16K Cassette 8 95 Disk 13 95 0 amp Try to manoeuvre your space ship through the meteor storms then land it carefully at the space port without running out of fuel or crashing Complete with realistic graphics STARFIRE AND NOVA INVASION L2 16K Cassette 10 95 Disk 15 95 60c p amp p Both programs include sound to improve their realism STARFIRE seats you in the cockpit of an X wing fighter as you engage in battle with the deadly Darth Vader s Tie fighters Beware of the evil one himself and may the Force be with you In NOVA INVASION you must protect your home planet of Hiberna from the invading NOVADIANS You have two fixed guns at each side of the screen and a moveable one at the bottom Apart from shooting down as many invaders as possible you must protect your precious hoard of Vitaminium or perish AIR ATTACK AND NAG RACE L2 16K Cassette 10 95 Disk 15 95 60c p amp p An unlikely combination of programs but they share the same author who has a keen sense of humour AIR ATTACK includes sound and realistic graphics The air craft even have rotating propellors B
76. ncy bit is the ANDing of the MSs of the screen pointer to determine if it s past the start of the screen having commenced at the end As the screen starts at 3C H it is convenient to be able to test that as soon as the MSB does not have CH as its low order nibble nibble 4 bits so high and low order nibble for each hex digit in a byte the screen address is no longer pointed to So having got a response from a reader I anxiously await more MICRO 80 has already installed a bigger letterbox to hold them all so don t let it go to waste 0000000000 THE THEORY AND TECHNIQUES OF SORTING PART 4 by B Simson The last article demonstrated some variations to the general method of sorting by insertion By now you would be under the impression that sorting by insertion is a very popular sorting technique if only for the number of different variations possible to the main theme Some fairly efficient variations have emerged all with their own advantages However all of these variations so far have one thing in common They are all subject to the restrictions inherent ca linear sequential data structure the array You can only stretch an elastic so far then it snaps A NEW DATA STRUCTURE What we need is something of a different nature that allows for increased efficiency without overbearing complexity Before introducing this structure of different nature examine one of the major disadvantages in all of t
77. nd new product reviews COPYRIGHT All the material published in this magazine 15 under copyright That means that you must not copy it except for your own use This applies to photocopying the magazine itself or making copies of programs on tape or disk LIABILITY The programs and other articles in MICRO 80 are published in good faith and we do our utmost to ensure that they function as described However no liability can be accepted for the failure of any program or other article to function satisfactorily or for any consequential damages arising from their use for any purpose whatsoever VOLUME 3 NO 3 FEBRUARY 1982 EDITORIAL INPUT OUTPUT READERS REQUESTS MICROBUGS BETTER BASIC PROGRAMMING PART 7 THE THEORY AND TECHNIQUES OF SORTING PART 4 80 USERS GROUPS MICRO 80 PRODUCTS MICRO 80 CONTENTS HOW TO USE THE TRS 80 LEVEL I ARRAY EFFECTIVELY TRANSFERRING TOUCHTYPE TO DISK DESCRIPTION OF FUNCTIONS PERFORMED BY THE EXPANSION INTERFACE SOFTWARE SECTION NEXT MONTH S ISSUE CASSETTE DISK EDITION INDEX ORDER FORM MICRO 80 is registered by Australia Post Publication SQB 2207 Category B AUSTRALIAN OFFICE AND EDITOR MICRO 80 P O BOX 213 GOODWOOD SOUTH AUSTRALIA 5034 TEL 08 211 7244 U K SUBSCRIPTION DEPT Printed by Published in Australia by 24 WOODHILL PARK PEMBURY TUNBRIDGE WELLS KENT TN2 4NW Shovel amp Bull Printers 379 South Road MILE
78. ndicated that a security firm in Sydney had the Ausiralian distribution rights for the ACT controller seemingly a strange combination Anyway once the advertisement appeared in APC I called the number indicated and almost before we knew it Eddy Paay and I were on a plane hotfoot literally it was during the power restrictions in February for Sydney I am happy to report that all innocence had not been lost Watching a 5M byte Winchester drive quietly and efficiently store and retrieve data in the blink of an eye was as great a thrill as that first disk drive had been 33 years ago The most impressive aspect of the whole demonstration however was the the skilful combination of hardware and software which makes the ACT hard disk sub system live up to its name as a system This is definitely not just another piece of advanced hardward technology which leaves the new owner with the responsibility for finding how to use it in his system This is a complete operating integrated hardware software package that will plug in and run efficiently and effectively Before we continue with more details of the sub system a few comments about ACT itself may be of interest ACT was indeed an American company which developed computer systems for use in large security installations Burglar alarms as they used to be called become very complex when large premises are being protected and computers have been used to do the job for some years ACT used the Zenith
79. nds without dis turbing the resident program Includes Superzap 3 0 which enables you to display print modify any byte in memory or on disk Also includes the following utilities Disk Editor Assembler Disassembler Z80 machine code LM offset allows transfers of any system tape to Disk file automatically relocated LEVEL I Lets you convert your computer back to Level 1 LVIDKSL Saves and loads Level 1 programs to disk DIRCHECK Tests disk directories for errors and lists them ASPOOL An automatic spooler which routes a disk file to the printer whilst the computer con tinues to operate on other programs LCDVR a lower case drives which display lower case on the screen if you have fitted asimple lower case modification DISK DRIVE USERS ELIMINATE CRC ERRORS AND TRACK LOCKED OUT MESSAGES FIT A PERCOM DATA SEPARATOR 37 00 plus 1 20 p amp p When Tandy designed the T RS 80 expansion interface they did not include a data separator in the disk controller circuitry despite the manufacturer s recommendations to do so The result is that many disk drive owners suffer a lot of Disk 1 0 errors The answer is a data separator This unit fits inside your expansion interface It is supplied with full instructions and is a must for the serious disk user PAGE 17 MPI DISK DRIVES HIGHER PERFORMANCE LOWER PRICE MPI is the second largest manufacturer of disk
80. or Driver program listed in MICRO 80 s November issue for the sake of simplicity The program is best entered via an editor assembler for a number of reasons 1 The copyright messages will be printed whilst loading thus indicating that the program is loading correctly 2 It is much easier to use a DEFM statement rather than to calculate the hex equivalent of each individual character 3 The program will run itself without typing If the program is entered by an editor assembler ignore the first two columns of the LISTing and type in the source code starting at line 117 label VIDEO may be changed to position the message anywhere on the screen the top line is most suitable due to linefeed action One word of caution the first character of your message in line 1130 must not be a space as the message will not flash if this is done The program sets memory size by itself as explained by Eddy in the HICRO 80 November issue and so it is not necessary to answer MEMORY SIZE or READY Disk BASIC users should use location 4 49H for TOPMEM and delete lines 380 to 490 inclusive and lines 1197 to 1290 The program may also be entered via a monitor BMON would not be suitable here without the addition of a block move routine described in the September 1980 issue of MICRO 80 7 L from the MICRO 80 Software Library would be suitable In this case the object code should be entered directly s arting at location 7EE5H by ent
81. other microcomputer with a Centronics parallel port RS 232 serial interface available shortly ET 121 typewriter 15 renowned for its quality fast speed 17 c p s quietness and reliability MICRO 80 is renowned for its knowledge of the TRS 80 SYSTEM 80 and its sensible pricing policy Together we have produced a dual purpose machine an attractive modern correcting typewriter which doubles as a correspondence quality Daisy wheel printer when used with your micro computer How good is it This part of our advertisement was typeset using an 121 driven by a TRS 80 Write and ask for full details BUY YOUR MODEL 3 FROM MICRO 80 AND SAVE 000 s MICRO 8O WINCHESTER DISK SYSTEM MICRO 80 fits reliable MPI disk drives to the TRS 80 Model 3 to give system capacities and capabilities far in excess of those available elsewhere All our conversions utilise low dissipation switching mode power supplies to avoid screen jitter and overheating The disk controller boards used incorporate special compensation circuitry for 80 track disk drives and may also be used to run 8 inch disk drives with an appropriate cable and DOS MODEL 340 2 40 TRACK SINGLE HEAD DISK DRIVES GIVING 350K FORMATTED STORAGE 48K RAM 3130 MODEL 340 2 40 TRACK DUAL HEAD DRIVES GIVING 700K FORMATTED STORAGE 48K RAM 3350 MODEL 380 2 80 TRACK DUAL HEAD DRIVES GIVING 1 4 MEGABYTE FORMATTED STORAGE 48K RAM 3800 NEW NE
82. ound that the Expansion Interface performs all these functions for what is quite a modest price when compared with the expansion connectors for computers like the Apple and with the exception of Tandy s 220 for 16K RAM price tag MICRO 80 s is faster and only 30 for 16K is good value 0000000000 SOFTWARE SECTION x x SCREEN COPY UTILITY L2 m 1 by N J Coleman This program provides two extra BASIC instructions which enable a copy of the screen display to be stored and recalled at will The program provides these two commands LSET to store an image of the screen RSET to recall an image Both commands are reasonably self explanatory Since the program is in machine language it is very fast instantaneous to the user This makes it ideal for graphics and board game programs where a design must be redrawn constantly The program is very simple for a BASIC user First set Mem Size to 31690 and then key in the program Once the program has been RUN it may be deleted and the two new commands used in any BASIC Program Change Line 230 to 230 DELETE 230 For a machine language programmer this program is simplicity itself All it does 15 i set up the LSET and RSET vectors and return to BASIC ii upon the respective commands being used either the screen memory is moved to a reserved portion of high RAM or the reserved RAM is moved to the screen locations all done using the LDIR
83. ow to send in your contribution Date seed g 5 9 amp 2 c 5 E 5 Az t 259 Oro Las 2 lt OuZ l a a lt Address Publication on disk or cassette only Both Names ists a MICRO 80 SOFTWARE DEPT 0 BOX 145 MORPHETTVALE SA 5162 Publication in MICRO 80 Please consider the enclosed program for i ii iii Postcode CHECK LIST suggested in case the program becomes separated from the accompanying literature Please package securely padabags are suggested and enclose stamps or Ensure that you supply adequate instructions notes on what the program postage if you want your cassette or disk returned System etc The use of REM statements with your name and address is does and how it does it etc Please ensure that the cassette or disk is clearly marked with your name and address program name s Memory size Level 11 System 1 or 2 Edtasm The changes or improvements that you think may improve it For system tapes the start end and entry points etc VOLUME 3 NO 3 FEBRUARY 1982 MICRO 80 PAGE 36 5 5 EDITION INDEX The cassette edition of MICRO 80 contains all the software listed each month on cassette All cassette subscribers need do is CLOAD and RUN the programs Level II programs are recorded on side 1 of the cass
84. phase the tables will be scanned and the variables listed for a cross reference new names will be allocated and listed if required and the lines in which the variable occurs will be listed An unusual feature is that names are allocated in decreasing frequency of occurr ence in order that space may be saved when allowing single letter names In the final phase if required the program is scanned again and the old variable names replaced by the new names Once again the graphics byte wiggles to confirm that the program is working When loaded the program displays the following menu RETURN TO BASIC COMPLETE RENAME OF VARIABLES SPECIFIED VARIABLE RENAMING CROSS REFERENCE ONLY XU Typing B simply returns to BASIC leaving the amended program intact in memory Type C and LONGVAR will display ENTER VARIABLE NAMES THAT YOU WISH TO DECLARE IZ ALL NAMES THAT INCLUDE RESERVED WORDS THE TYPE BYTE MUST BE INCLUDED PRESS ENTER AFTER EACH ONE ENTER TO TERMINATE VOLUME 3 NO 3 FEBRUARY 1982 MICRO 80 PAGE 26 You should now type in any variable names that you have used that included reserved words i e FORKS this contains the reserved word FOR STIFF this contains the reserved word IF Note also the inclusion of the type byte even if the variable appears in your program as STIFF it must be identified for LONGVAR as STIFF The program will then ask you PRESS Y IF YOU SPECIFIED ANY VARIABLES
85. place and KNIEVEL as in motorcycle ramp and buses OTHER PROGRAMS INFINITE BASIC BY RACET 32K 1 DISK 49 95 50c p amp p Full matrix functions 30 BASIC commands 50 more STRING functions as BASIC commands GSF L2 48K 24 95 50c p amp p 18 machine language routines including RACET sorts BUSINESS ADDRESS AND INFORMATION SYSTEM 48K DISK 24 95 50c p amp p Allows you to store addresses and information about businesses edit them and print them out HISPED L216 32 or 48K 29 95 This machine language program allows you to SAVE and LOAD programs and data to tape at speeds up to 2000 band 4 times normal using a standard cassette recorder A switch must be installed to remove the XRX III loading board if fitted PAGE 20 LOWER CASE FOR YOUR TRS 80 SYSTEM 80 Kit only 49 00 plus 2 00 p amp p Give your TRS 80 or SYSTEM 80 a lower case display with proper descenders and a block cursor similar to the TRS 80 Model 111 Also includes symbols for the four suits of cards Includes full fitting instructions all necessary components and a special machine language driver program to enable lower case in BASIC The modification is similar to the Tandy model and does not work with Electric Pencil without further modifi cations These kits require disassembly of your computer and some soldering They should only be installed by someone who has experience in soldering integrated circuits using a low power properly
86. r disabling the BREAK key as well as the routine above However they all require knowing that the BREAK key will force a jump to 400 16396 decimal If you have a disk system TRSDOS will have put an address there to make the BREAK key the method of jumping to DEBUG From which it follows that you can also put something there to provide your own handling of the BREAK key Other systems have a statement of ON BREAK GO TO but we can simulate this quite easily Normally level II will have 191 RET at 16396 I use decimal here because you will probably be doing these modifications from BASIC when you require a decimal address Which means it will just return with whatever is in the A register the ROM Reference Manual tells you A holds the result of the keyboard scan So this leaves the way open for us to operate on the A register before it gets back You will remember that I suggested in the first episode that you could simply POKE 16396 23 to disable the BREAK key in level II This is in effect rotating the accumulator left 23 decimal 17H RLA which means it no longer holds 1 the value of the BREAK key and it will RETurn on encountering the 201 RET that level II has at 1640 But you will also remember I suggested that this is a bit simple and it won t work for a disk system If you zero the accumulator by POKEing a value to do so 151 97H SUB A 175 AFH XOR A into 16396 then a 201 C9 RET into 16397
87. recorder and to save the music data to tape This is an improved version of the program published in Issue 17 of Micro 80 PAGE 1 VOLUME 3 NO 3 FEBRUARY 1982 MICRO 80 PAGE 2 EDITORIAL How vividly I remember the thrill all those years ago about 33 to be precise when I eagerly unpacked the first disk drive for my Model I TRS 80 connected it up and marvelled at the speed efficiency and above all the reliability of its data storage compared with the cassette recorder I had been using Time has passed the old 35 track single side single density disk drive has given way to the larger capacity 40 track drives then dual head and even 80 track dual head drives and finally double density operation all supported by more and more powerful disk operating systems But none of these developments gave the same thrill as that first humble 35 track disk drive They were evolutionary it was revolutionary I thought that innocence had well and truly been lost and that that sort of excitement was gone forever Recently I noticed an advertisement in Australian Personal Computer for micro winchester drives using ACT 506 controller boards ACT was not an unfamiliar name I had seen similar advertisements in the American Byte magazine several months earlier but that ACT stood for American Computers and Telecommunications whilst this stood for Australian Computers and Telecommunications Enquiries to the States at the time had i
88. reen and sounded in a sequence determined by the computer Your task is to reproduce the sequence correctly LINE Rather like a super complicated version of noughts and crosses You may play against another player or against the computer itself But beware the computer cheats SUPER CONCENTRATION Just like the card game but with more options You must find the hidden pairs You may play against other people play against the computer play on your Own or even let the 80 play on its own TRIAD VOL 2 L2 16K Cassette 10 95 Disk 15 95 60c p amp p Remember those NUMERO puzzles in which you had a matrix of numbers or letters with one blank space and you had to shuffle the numbers around one at a time until you had made a particular pattern Well SHUFFLEBOARD the first program in this triad is just this except that the computer counts the number of moves you take to match the pattern it has generated so it is not possible to cheat MIMIC is just like SHUFFLEBOARD except that you only see the computer s pattern for a brief span at the beginning of the game then you must remember it In MATCHEM you have to manoeuvre 20 pegs from the centre of the screen to their respective holes in the top or bottom rows Your score is determined by the time taken to select a peg the route taken from the centre of the screen to the hole and your ability to direct the peg into the hole with out hitting any other peg or the boundary VISU
89. rograms The driver routines are self relocating self protecting and will co reside with other machine language programs such as Keyboard debounce serial interface driver programs etc plus 2 00 Both programs give your TRS 80 Model or System 80 an optional typewriter capability i e shift for upper case The second programme also includes Keyboard debounce and a flashing cursor You fit it Or we can Fitting the modification requires soldering inside the computer This should oniy be carried out by an experienced hobbyist or technician If you are at all dubious a fitting service is available in all capital cities for only 20 00 A list of installers is included with each kit ADD A DISK DRIVE TO YOUR TRS 80 MODEL III FOR ONLY 875 00 OR ADD TWO FOR ONLY 1199 The Micro 80 disk drive upgrade for the TRS 80 Model III contains the following high quality components 1 or 2 MPI 40 track single head disk drives 1 VR Data double density disk controller board and 1 dual drive power supply plusall the necessary mounting hardware cables and comprehensive fitting instructions which can be carried out with a minimum of fuss by any average computer owner Fitting service isavailable for 25 00 in mostcapital cities ONLY 2049 INC S T Daisy Wheel Typewriter Printer MICRO 80 has converted the new OLIVETTI ET 121 DAISY WHEEL typewriter to work with the TRS 80 and SYSTEM 80 any
90. s carried out by different parts of the program Lines 80 140 Ask for information to be input 217 230 Read the TAX SCALES from the DATA in lines 419 449 260 280 the TAX SCALES for the Lower Limit LL that is greater than the Net Income TI 290 Ensures that if Net Income is greater than last DATA line 440 that this line is used 310 Calculates the Tax Payable IT by going back one DATA line 320 Prints Tax Payable 350 379 Print out Who Owes Who and how much 419 440 DATA lines which store the Tax Scales This progrza is correct for the 1980 81 Tax Year 0000000000 VOLUME 3 NO 3 FEBRUARY 1982 MICRO 80 PAGE 29 00010 MESAGE 00020 s 00030 THIS ROUTINE FLASHES A MESSAGE INDEPENDENTLY OF PROGRAM 00040 CONTROL MEMORY SIZE IS SET AUTOMATICALLY AND PROGRAM 00050 RUNS BY ITSELF IF ENTERED VIA AN EDITOR ASSEMBLER 00060 PROGRAM IS DISABLED BY KILL COMMAND IN BASIC AND 00070 ACTIVATED BY THE LOAD COMMAND 00080 THE RATE OF FLASHING MAY BE ADJUSTED BY FOLLOWING 00090 BASIC PROGRAM OTHERWISE IT IS SET TO DEFAULT VALUE 00100 3DCO 00110 ORG 3DCOH 3DCO 2A 00120 DEFM xk kk FLASHING MESSAGE ROUTINE C JULY 1981 kr 20 00130 DEFM gt BY ANTHONY PARK MIDDLE COVE N S W 2068 00140 PROGRAM FOLLOWS 00150 7EES 00160 ORG 7EESH 00170 00180 DEFINE LABELS 00190 O6CC 00200 BASIC EQU 00210 KBSCAN EQU 4016 00220 KB
91. s whilst those readers in the Middle East and other tax havens can reinforce the wisdom of their choice of domicile The following variables are used in the program LL Lower Tax Limit TD Tax Dollar Payable on LL TC Tax Cents Payable on LL GC Gross Income from Group Certificate OI Other Income apart from group certificate DD Deductions TI Taxable Income TP Tax Paid IT Income Tax Payable The Tax Scales themselves are contained in DATA Lines 410 440 These should be altered whenever the Tax Scales chance As an example shown below are the Tax Scales in two financial years 1979 1980 and 1980 81 and the changes which would have been required in the DATA Lines Tax Scales 1979 1980 Taxable Income Tax on Taxable Income From To 1 3893 NIL 3893 16607 NIL plus 33 07 cents for each 1 above 3893 16608 33215 4204 8505 plus 47 07 cents each 1 above 16608 33216 and over 12022 326 plus 61 07 cents each 1 above 33216 Tax Scales 1980 1981 1 4041 NIL 4041 17238 NIL plus 32 cents for each 1 above 4041 17239 34477 4223 36 plus 46 cents for each 1 above 17239 34478 and over 12153 30 plus 60 cents for each 1 above 34478 DATA Lines DATA Lines 1979 1380 1980 1981 412 DATA 1 1 420 DATA 3893 2 2 3307 4741 0 32 430 DATA 16608 4204 85 0 4707 17239 4223 36 7 46 440 DATA 33216 12722 236 0 6197 34478 12153 30 0 60 ANALYSIS OF THE PROGRAM The following shows the function
92. sizes of 16 1648 164844 16481442 and 16484144241 DIMINISHING INCREMENT SORT Let n total number of items being sorted p number of passes c number of comparisons C Since 2 n p 7 i e INT LOG N LOG 2 on C in Pass 1 2 55 2 in Pass 3 tyt in Pass P 5 i tg 2 i This represents the summation of a geometric progression of general formula A 1 RN where A R 1 R N first term common ratio nth term In this case A R Set N Pn Pass n Substituting C in Pass Pn z a gan n 1 1 2Ph 7 So no comparisons in any pass is given by formula n 1 1 2P where Pn Pass number 1 24 Ciotal n 1 7i n 1 z where total number of passes 11 1 1 1 1 55 1 29 2 2 a n 1 1 1 15 2 il i VOLUME 3 NO 3 FEBRUARY 1982 MICRO 80 PAGE 15 The inner parenthesis also represents a summation of a geometric progression where A 3 R 3 n Also since the units have been extracted from each pass parenthesis their sum must equal 1 1 30 97 Substituting Ciota n P n p 1 1 2P 1 n P 1 P Now as the number of passes p becomes large 1 becomes insignificant and 2P becomes huge causing 1 become insignificant 2P Therefore Ctotal approx n P Since log log 2 Ctotal approx n Log n
93. stralia by airmail to other countries at the following rates 12 MONTH SUB MAGAZINE CASS MAG DISK MAG PAPUA NEW GUINEA Aus 40 00 Aus 83 00 Aus 143 00 HONG KONG SINGAPORE Aus 44 00 Aus 88 00 Aus 148 00 INDIA JAPAN Aus 49 00 Aus 95 00 Aus 155 00 USA MIDDLE EAST CANADA Aus 55 00 Aus 102 00 Aus 162 00 Special bulk purchase rates are also available to computer shops etc Please use the form in this issue to order your copy or subscription The purpose of MICRO 80 is to publish software and other information to help you get the most from your TRS 80 System 80 or Video Genie and their peripherals MICRO 80 is in no way connected with either the Tandy or Dick Smith organisations WE WILL PAY YOU TO PUBLISH YOUR PROGRAMS Most of the information we publish is provided by our readers to whom we pay royalties An application form containing full details of how you can use your TRS 80 or System 80 to earn some extra income is included in every issue CONTENT Each month we publish at least one applications program in Level I BASIC one in Level II BASIC and one in DISK BASIC or disk compatible Level II Me also publish Utility programs in Level II BASIC and Machine Language At least every second issue has an article on hardware modifications or a constructional article for a useful peripheral In addition we run articles on programming techniques both in Assembly Language and BASIC and we print letters to the Editor a
94. t move the entry point if necessary the sound will stay with you No it s not hard I added the necessary 4 bytes to the BIG FIVE game Attack and can tell you that s all that is necessary However a better way is a hardware modification to get the sound directly from the board which will give a far better tone than even the TRS 80 s AUX line does without any modifications 7FOO 00100 ORG 32512 7FOO CD7FOA 011 ENTRY CALL OA7FH GET VALUE FROM USR O IN BASIC 7 00120 LD 140 LENGTH OF NOTE TIMES CYCLE REPEA TED 7 5 45 REPEAT LD B L VALUE FROM USR O CAN BE 255 7Fe 6 00140 LD A 1H VALUE FOR POSITIVE VOLTAGE 7F68 D3FF 00150 OUT OFFH SEND PULSE OUT PORT 7FOA 1 FE HIVOLT DJNZ HIVOLT DELAY FOR NUMBER CYCLES IN USR O PITCH 7FOC 45 00170 LD B L VALUE FROM USR O 7FOD 2 00150 LD A 2H VALUE FOR NEGATIVE VOLTAGE 7FOF D3FF 00170 OUT OFFH A SEND PULSE OUT PORT 255 7F11 1 FE 0200 LOVOLT DJNZ LOVOLT DELAY 7F13 OD 00210 DEC sAFTER ONE WHOLE CYCLE COMPLETED 7F14 2 EF 0022 JR NZ REPEAT REPEAT 14 TIMES VALUE IN C 7F16 C9 00230 RET BACK TO BASIC 7FOO 00240 END ENTRY This is the simple sound generator program I presented at the end of the LIST disable routine in BASIC last article The comments make the source code fairly self explanatory Because of the speed of machine code it has been necessary to incorporate delays into the program
95. t LONGVAR is still alive The S function on the program menu allows you to rename specified variables whilst leaving the other variables in your program alone When selected the program will display ENTER VARIABLE NAMES THAT YOU WISH TO ALTER USING THE FORM VT N T WHERE V V IS THE OLD NAME T IS THE TYPE BYTE AND N N IS THE NEW NAME PRESS ENTER AFTER EACH ONE ENTER TO TERMINATE Using our previous example variables they would be typed in exactly as follows STIFF A FORK 8 or if the old names had no type byte then you would type STIFF A FORK B or STIFF A FORK 8 Remember though if you use the last example LONGVAR does not check or change DEF statements So if at the beginning of your original program you had DEFSTR F and you used the last example of FORK B without type flags then you should also change the DEF statement to DEFSTR B When renaming starts the program will list the variables being changed whilst wiggling the graphics dot previously mentioned VARIABLE STIFF RENAMED TO A IN LINE 10 VARIABLE FORK RENAMED TO B IN LINE 95 etc etc VOLUME 3 NO 3 FEBRUARY 1982 MICRO 80 PAGE 27 The last function X in LONGVAR simply lists out all the variables in the program and the lines that they are in program provides the option for this listing to go to the VDU or the printer e g VARIABLE A IN LINE 70 80 90 100 VARIABLE A IN LINE 65 90 78 105 VARIABLE B IN LINE 200
96. t the Model III For example the following video capabilities are supported HEX EFFECT 08 Backspace and erase 09 Tab 8 16 24 OA Move cursor to start of next line and erase line 00 cursor to start of next line and erase line OE cursor on OF cursor off 15 Swap space compression Special Characters 16 Swap special Alternate Characters 7 double size characters 18 Back space without earsing 19 Advance cursor 1A cursor down line 1B Cursor up line 1 Home cursor 1D Erase line and start over Erase to end of line Erase to end of screen The CP M 2 2 supplied contains the following standard CP M programs and files MOVCPM COM Program to relocate the CP M system PIP COM ru to move files Modified to use characters instead of SUBMIT COM Program to perform batch processing ED COM Text file editor ASM COM 8080 assembler DDT COM System debugger Modified to use RST6 LOAD COM Generates COM files from HEX files STAT COM Program to display set system and file parameters DUMP COM File dumper DUMP ASM Source of above There are several additional programs supplied on the diskette These are special programs written by ACT personnel to aid in system generation and error analysis All are supplied in both source and object form SYSGEN ASM Special system generation program for use with TRS 80 Model III SYSGEN COM floppy drives and 5MB hard disk Program operat
97. that here The Government in its munificence allows one or two minor items of expenditure as deductions i e non taxable After identifying these the taxpayer is then required to calculate his net taxable income and thence the tax which is payable from a table supplied The majority of the population works for someone else and pays tax each week or month on a pay as you earn PAYE scheme These people complete an S for Salaries and Wages Income Tax Return Form Having calculated how much tax he should have paid and knowing from the Group Certificate supplied by his employer how much he has paid the taxpayer then completes the form sends it off and waits expectantly if the Taxation Department owes him money or with great anxiety if the opposite is true Once upon a time the Government always made sure that everyone overpaid under the PAYE scheme thus everyone was entitled to a refund often of several hundred dollars Such a situation perpetrated by anyone else would of course be fair game for all the consumer protection author ities etc but passed with little comment except from a few cranks Indeed from August on one was treated to the curious sight of taxpayers rejoicing as they received back their own money which had been forcefully removed from them over the previous 12 months This became a popular source of mad money and many projects were financed by the refund cheques Holidays were taken new carpets purchased ev
98. ttes Dosplus Price Version DRIVE TYPE Capacity All disk drive components are still available separately BARE DRIVES MPI drives offer the fastest track to track access time 5 milliseconds available All drives are capable of operating in double density for 80 greater storage capacity Price Freight Price Freight MPI B51 40 track single head 100K 399 caprice 500 Self contained single drive cabinet power supply 99 5 00 MPI B52 40 track dual head 200K 449 5 Self contained dual drive cabinet power supply 135 5 00 MPI B92 80 track dual head 400K 9619 5 00 Two drive cable 39 2 00 2 00 drive cable 49 2 00 8 00 DOSPLUS 5 5 99 95 2 00 DOSPLUS 3 4 149 95 2 00 Simple wrap around cabinet 12 Separate dual drive power supply 85 Prices are FOB Adelaide Add 5 00 freight for single drive package 10 00 for dual drive package Prices are in Australian dollars Freight is road freight anywhere in Australia All items carry a 90 day parts and labour warranty Repairs to be carried out in our Adelaide workshops PAGE 49 SOFTWARE BY AUSTRALIAN AUTHORS All our software is suitable for either the SYSTEM 80 or the TRS 80 NEW SOFTWARE FROM MICRO 80 PRODUCTS BUSINESS PROGRAMS MICROMANAGEMENT STOCK RECORDING SYSTEM L2 16K Cassette version 29 95 1 00 p amp p Stringy Floppy version 33 95 1 00 p amp p This system has been in use for 9 months in
99. type NEW makes one program invisible while you work on a second saves hours of cassette time lists all the variables used in the program makes SYSTEM tapes lets you Edit memory directly the list goes on and on Cassette comes with 16K 32K and 48K versions ready to load Can anyone afford NOT to have BMON EDUCATIONAL RPN CALCULATOR L2 16K amp 32K 514 95 50c p amp p Give your computer the power of a 650 reverse polish notation calculator with 45 functions and selectable accuracy of 8 or 16 digits The main stack and registers are continuously displayed whilst the menu is always instantly accessible without disturbing any calculations or register values The cassette comes with both the 16K and 32K versions the latter giving you the addi tional power of a programmable calculator Comes with a very comprehensive 15 page manual which includes instructions to load and modify the 32K pro grammable version to run in 16K Whether for business or pleasure this package will prove invaluable and turn you 80 into a very powerful instrument GAMES MICROPOLY L2 16K 8 95 60c p amp p Now you can play Monopoly on your micro The old favourite board game has moved into the electronic era This computer version displays the board on the screen obeys all the rules and best of all the banker does not make mistakes with your change CONCENTRATION L2 16K 8 95 60c p amp p Another application of supergraphics There
100. uilt up and tested in an attractive cabinet with a self contained power supply ready to plug in and go The expansion interface carries MICRO 80 s full no hassle 90 day warranty Features include Sockets for up to 32K of memory expansion e Disk controller for up to 4 disk drives o Parallel printer port Serial RS232C 20mA 1 0 port e Second cassette optional The expansion interface connects directly to your TRS 80 L2 16K keyboard or via SYSPAND 80 to your SYSTEM 80VIDEO GENIE Prices HD 010 A Expansion Interfaces with K 499 00 HD 010 B Expansion Interfaces with 32K 549 00 HD 011 Data separator fitted recommended add 29 00 HD 012 Dual cassette Interfaces fitted add 19 00 The MICRO 80 Expansion Interface is also available in kit form Prices HD 013 Kit consisting of LNW Research PC board and manual ALL components including cabinet amp power supply 375 00 HD 011 Data separator for above 25 00 HD 013 Dual cassette Interface kit 15 00 649 choice of upper and lower case display ts easier to read gives greater versatility The Micro 80 lower case modification gives you this facility plus the symbols for the 4 playing card suits for 49 00 2 00 p amp p The Micro 80 modification features true below the line descenders and a block cursor Each kit comes with comprehensive fitting instructions and two universal lower case drive routines on cassette to enable you to display lower case in BASIC p
101. ut they also drop bombs on you so it s kill or be killed NAG RACE lets you pander to your gambling instinct without actually losing real money Up to five punters can join in the fun Each race results in a photo finish whilst there is a visible race commentary at the bottom of the screen throughout the race Happy punting FOUR LETTER MASTERMIND L2 16K Cassette 8 95 Disk 13 95 60c p amp p There are 550 four letter words from which the computer can make its choice You have 12 chances to enter the correct word After each try the computer informs you of the number of correct letters and those in the correct position You can peek at the list of possible words but it will cost you points Makes learning to spell fun MUSIC IV L2 16K Cassette 8 95 Disk 13 95 60cp amp p Music IV is a music compiler for your 80 It allows you to compose or reproduce music with your computer that will surprise you with its range and quality You have control over duration full beat to 1 16 beat with modifications to extend the duration by half or one third for triplets Both sharps and flats are catered for as are rests Notes on whole sections may be repeated The program comes with sample data for a well known tune to illustrate how it is done x SAVE 0095 x SAVE 0095 x x SAVE 00 s x x x MICRO 80 EXPANSION INTERFACE x xx MICRO 80 s expansion interface utilises the proven LNW Research Expansion board It is supplied fully b
102. y It has two arguments passed to the machine language routine which returns in the middle of itself as well as one POKEd into fixed RAM But a re reading of Ron Sully s article Sound Effects Revisited in Issue 22 may make it clearer What it does show though is that our 80 is indeed capable of some wondrous things but you already knew this from Ron s program Going even further and without the hardware provided by Orchestra 80 there is a program called Opera which does as Ron suggests uses the BASIC interpreter to produce such works as The William Tell Overture So with thought experimentation and perseverance much is possible A READER RESPONDED Being shocked horrified and disgusted at the gross inefficiency of my screen white out routine presented two issues ago a reader Eddy Paay has provided this code to do the same 3FFF 00100 VIDRAM EQU 3FFFH END OF SCREEN RAM OOBF 00110 WHITE EQU OOBFH CODE FOR SOLID GRAPHIX BLOC K 00120 7 00130 ORG 32512 7FOO 21FF3F 00140 START LD HL VIDRAM POINT TO END OF SCREEN 7FO3 36BF 00150 LOOP LD HL WHITE WHITE OUT CURRENT SCREEN PO SITION 7FOS 2B 00160 DEC HL POINT TO NEXT BACKWARDS S CREEN POSITION 7FO6 7C 00170 LD A H LOOK AT MSB SCREEN ADDRESS 7FO7 E604 00180 AND 4 315 SCREEN POINTER lt 3CH 7 09 20F8 00190 JR NZ LOOP IF NOT CONTINUE 7FOB C9 00200 RET FINISHED SO RETURN TO BASI 7FOO 00210 END START I think the comments make all clear the only fa
103. y and extend LEVEL III BASIC 59 95 plus 1 20 p amp p Loads on top of Level BASIC and gives advanced graphics automatic renumbering single stroke instruc tions shift key entries keyboard debounce suitable for L2 16K and up Not Disk BASIC ADVENTURE ON DISK 35 95 plus 1 20 p amp p This is the original ADVENTURE game adapted for the TRS 80 The game fills an entire diskette Endless variety and challenge as you seek to rise to the level of Grand Master Until you gain skill there are whole areas of the cave that you cannot enter Requires 32K One Disk BASIC COMPILER 5208 plus 2 00 p amp p New improved version the Basic Compiler converts Disk BASIC programs to machine code automatically A compiled program runs on average 3 10 times faster than the original BASIC program and is much more difficult to pirate UPGRADE TO 16K FOR ONLY 30 00 MICRO 80 s 16K MEMORY EXPANSION KIT HAS BEEN REDUCED IN PRICE EVEN MORE Larger volume means we buy better and we pass the savings on to you These are our proven prime branded 200 ns yes 200 nanosecond chips You will pay much more elsewhere for slow 350 ns chips Ours are guaranteed for 12 months A pair of DIP shunts is also required to upgrade the CPU memory in the TRS 80 these cost an additional 4 00 All kits come complete with full step by step instructions which include labelled photographs No soldering is required You do not have to be an experienced

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