LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS - tim
Contents
1. The LDOS user s manual contains over 250 printed pages of information and the text takes up over half a Meg of storage on an 8 double density diskette It was written with Model I Scripsit running on the LDOS operating system The manual was started during the last week of December 1980 and went to press at the start of the second week in February 1981 In that 6 week period approximately 1800 man hours went into the writing and proof reading of the manual Since LDOS was also being fine tuned during that period revisions to the text were constantly being made The writing test printing proof reading re writing etc used up over 6000 sheets of paper and 2 dozen printer ribbons The normal work week for the people involved was 9 AM to whenever at least 6 days a week But we feel that the end result was well worth the work Your comments on the manual have been for the most part favorable and the manual seems to be serving its purpose rather well However it appears that a few errors did slip by the proof readers during some of their late night sessions What follows will be a list of corrections for the first edition Those of you with serial numbers ending higher than 1000 will probably have the second edition check the bottom of the Table Of Contents for the second edition message This list of corrections will not correct any typographical errors or misspellings Most of these were hopefully corrected in the second editi2. and it must be less than the first line number outside of the block to be renumbered Using the above example the easiest way to assign a value to the last parameter is to assign to it a number which is one less than the value of the first line number outside of the block to be renumbered i e 1349 Page 10 13 When using the CMD N command do NOT use the parameter unless you are absolutely sure no errors exist If you do not specify the parameter a full scan for errors will be done before renumbering starts If errors do exist no lines will be changed and any errors may be corrected at this time If you do specify the parameter any error found will abort the renumbering However all internal line number references will have been changed up to the line number that caused the error 14 For many Model I owners the idea of Blocked Files may be new The following examples will draw a comparison between the code needed to access conventional Model I random files as opposed to the code needed to access LBASIC Blocked Files In all examples below let us assume we are dealing with records whose Logical Record Length LRL is 25 bytes Also each logical record is divided into four fields Field 1 is 5 bytes long Field 2 is 4 bytes long Field 3 is 8 bytes long and Field 4 is 8 bytes long Let us assume that we wish to represent the variables in our field statement as an array Example 1A will represent a conve
3. 120 135 140 150 200 210 220 230 240 250 260 270 280 290 300 310 320 330 340 350 360 370 500 n REM UPDATE BAS REM Updates all LDOS files present on a disk REM by copying them from a disk containing REM the latest release REM Tim Mann 03 25 81 CLEAR 1000 DEF FNSS X LEFTS X INSTR X 1 DEF FNDS X RIGHTS STRS X 1 REM Initialize CLS PRINT INPUT Source drive D1 INPUT Destination drive D2 IF D1 D2 PRINT Source and destination drives cannot be the same GOTO IF D2 0 PRINT Destination drive cannot be drive 0 GOTO 130 PRINT D1S FND D1 D2 FND D2 REM Loop through directory OPEN RO 1 DIR SYS D1 32 FIELD 1 1 AS XF 4 AS XD 8 AS XN 3 AS XES FOR I 17 TO LOF 1 IF I 17 OR I 25 THEN 350 17 is BOOT SYS GET 1 1 25 is DIR SYS IF ASC XF AND amp H90 lt gt amp H10 THEN 350 Go if dead file NS FNSS XNS FNSS XES Form name ON ERROR GOTO 500 Skip if not on destination drive OPEN I 2 N P3UF D2 ON ERROR GOTO 0 CLOSE 2 CS COPY N RSOLTOFF D1 D2 PRINT Copying file NS CMD C Do COPY command NEXT I PRINT END RESUME 350 Page 23 FAST CMD This program will allow LX 80 interface owners to use a fast clock modification without hardware modification of the LX 80 interface See the article in this newsletter for more information It was contributed by Tim Mann 05 06 46 41 53 54 3A 32 01 59
4. or the BUILD command to create an ASCII file containing the hex code DO NOT leave spaces between the hex characters the spaces were put in for readability only The ASCII files must NOT contain more than 254 characters 127 byte pairs per line Page 20 2 Enter LBasic and Run the program BINHEX BAS choosing the mode BINHEX BAS Fol 10 20 30 35 40 50 100 110 120 130 140 150 200 210 220 230 240 250 255 260 270 300 310 320 330 340 400 410 420 430 440 450 455 460 470 480 490 500 505 510 520 530 580 580 580 580 580 600 lowing is the listing for the LBasic program contributed by Tim Mann REM Hex to binary Binary to hex file converter REM Tim Mann CLS PRINT PRINT Hex to binary Binary to hex PRINT file converter PRINT CLEAR 5000 GOSUB 58000 PRINT Type 1 to convert a binary file to hex PRINT 2 to convert a hex file to binary PRINT INPUT D PRINT ON D GOTO 400 200 GOTO 100 LINE INPUT Hex file name HFS LINE INPUT Binary file name BFS OPEN I 1 HFS OPEN O 2 BF IF EOF 1 THEN 320 LINE INPUT 1 D IF D OR D OK THEN 240 FOR I 1 TO LEN D STEP 2 PRINT 2 CHRS FND2 MIDS D 1I 2 NEXT I GOTO 240 CLOSE PRINT PRINT Done PRINT GOTO 100 LINE INPUT Binary file name BFS LINE INPUT Hex file name HFS OPEN RO 1 BFS 1 OPEN O 2 HF FIELD 1 1 AS F FOR 1 1 TO 30 IF EOF 1 THEN 505 GET 1 PRINT 2 FNH2 ASC F NEXT I PRI
5. 00 52 21 56 52 ED 5B 49 40 01 24 00 ED B8 ED 53 49 40 13 21 01 47 06 08 73 23 72 3E 09 85 6F 10 F7 21 25 52 C3 05 44 53 59 53 54 45 4D 20 28 46 41 53 54 29 OD E5 F5 21 OF 43 7E CB 9E 67 AF D3 FE F1 E3 CD 8A 30 E3 F5 7C 21 OF 43 CB 5F 28 06 3E 01 D3 FE CB DE F1 El C9 02 02 00 52 USRFREE CMD This is a short utility that can be called as a USR routine from LBasic and will return the amount of free K on a disk An empty or missing disk will return a zero To make a program module use the DEBUG command to enter the program into memory at the desired location and then use the dump command to save it to disk Do not use the BINHEX BAS program on this module To call this USR routine use the syntax X USR1 drivespec This routine was contributed by Chuck Jensen CD 7F OA 4D 7D CD B8 44 20 3D CD 8F 47 FD 46 06 04 FD 56 09 21 00 42 1E 00 CD 45 4B 11 00 00 78 06 08 CB 46 20 01 13 CB OE 10 F7 3D FE 00 28 03 23 18 ED EB FD 7E 08 3C E6 1F CD 8F 4B 65 6F 3E 04 CD A9 4B C3 9A OA 21 00 00 C3 9A OA UPCASE FLT This is a general filter for use with any device KI DO PR CL etc It will convert all characters to upper case This should be useful for those without lower case conversions It was contributed by Tim Mann 01 53 00 52 D5 DD El DD 6E 01 DD 66 02 22 3D 52 22 40 52 01 24 00 2A 49 40 AF ED 42 22 49 40 23 E5 EB 21 2D 52 ED BO El DD 75 01 DD 74 02 C3 2D 40 38 10 F5 79 FE 7F 30 06 FE 61 38 02 CB A9 F1 C3 00 00 CD 00 00 F5 FE 7F 30 08 FE 61 3
6. 11 shows the HIT positions assigned to LDOS SYStem files The proper HIT positions for SYS6 SYS13 should be positions 20 through 27 TECH INFO lt ENTRY POINTS gt Page 1 ADTSK should note that the HL register pair is used The correct text should read Note The DE register is a pointer not to the location of your task driver but to a block of RAM called the TCB which contains the address of the task driver entry point Upon entry to your task routine the register IX will contain the TCB address Page 10 the DODIR information was missing This text should go between DATE and DSPLY DODIR Vector X 4463 This routine will read visible files from a disk directory The screen display will be in a 4 across format The buffer will contain directory record bytes 0 15 and bytes 20 21 An X FF will indicate the buffer end B gt Option 0 Screen display 1 Buffer C gt Drivespec HL gt Buffer address if selected with B 1 Page 19 Page 14 PAUSE should say 14 67 microseconds not milliseconds Page 15 GETDCT should say This routine will obtain the address of the drive code table for the requested drive The IY register description should read the drive code table address TECH INFO lt MEMORY MAP gt X 4315 X 4317 text changed to used with DEBUG do not use X 4424 GOPEN text should read Open an existing file or device X 4428 CLOSE was missing from the original memory map The te
7. EQU 2 00420 LD HIGHS HL amp restore it 00430 LD SP 0 restore stack pointer 00440 SAVSP EQU 2 00450 RET reenter program 00460 00470 Save area for EXIT and ABORT vectors 00490 00500 LDOSSV DS 00510 k k during command execution 6 vector save area 00520 The following instructions are the vectors back to 00530 your program from EXIT and ABORT You may wish to 00540 treat EXIT differently from ABORT LDOSRET LDOSRET EXIT vector ABORT vector by Tim Mann One of the lesser known features of LDOS is its ability to work with TRS 80s that have been modified to speed up the CPU clock Unlike most other operating systems LDOS does not require any patches to work at a clock speed as high as 3 54 MHz or possibly higher It is also unnecessary to run a wire into your expansion interface to slow down the clock during disk I O as some speedup board manufacturers recommend If you have a clock speedup in your TRS 80 or are thinking of putting one in this article will help you understand this LDOS feature and guide you around some of the possible pitfalls Why does a disk operating system need to do something special to work with a speeded up clock As you might have expected there are certain time delay loops used in disk operations that will not function properly at increased CPU speed There are three areas in which some operating systems use delay loops or time wasting instr
8. LDOS LDO OS LDOS LD OS LDOS LD DOS LDOS L DOS LDOS L LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS S LDOS LDO S LDOS LDO OS LDOS LD OS LDOS LD DOS LDOS L DOS LDOS L LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS S LDOS LDO S LDOS LDO OS LDOS LD OS LDOS LD DOS LDOS L DOS LDOS L LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS S LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDO OS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LD DOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS L LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS S LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDO OS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LD DOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS L LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS S LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDO OS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LD
9. Logical Systems Inc Overseas updates must be accompanied by an international money order for 10 00 Model III LDOS should be ready for release at the end of June The price will be 149 00 and will include the Master disk and a full manual containing operating instructions and technical information The passwords for LDOS files were left out of the manual Refer to this list System files SYS WOLVES Filter files FLT GSLTD Driver files DVR GSLTD Utility files CMD RRW3 Basic overlay OV BASIC LOBO DCT RRW3 CONFIG SYS CCC User contributions to this newsletter have been almost non existent We receive many suggestions about new features that many of you would like to see in future releases of LDOS Many of you have written routines that add these features as separate programs or high memory drivers Why not contribute them to your LDOS Newsletter so that all LDOS owners can use them To those of you that have already contributed to the newsletter or the MicroNET bulletin board database many thanks from all who have made use of your programs For those of you who are legal owners of more than one LDOS you can refer to these as your LDii not LDOSes Want to clear the screen inside of a JCL Try the command MEMORY GO X 1C9 Page 3 This short program will cause a Top of Form to be sent to the lineprinter Use the BUILD command with the Hex parameter to build the program T CMD as follows BUILD T CMD HEX The
10. Z2 pin 6 on the Archbold board to Z37 pin 1 on the TRS 80 CPU board This causes the board to be reset to slow whenever the SYSRES line goes low which occurs on powerup when the Reset button is pressed and when the BOOT library command is used which causes the CPU to execute a HALT instruction The nice thing about this mod is that it enables you to boot on any disk including a foreign operating system with no provisions for handling a fast clock I am told that if you have the new version of the Archbold board which does not have a resistor or capacitor on the board you can accomplish the same thing by removing the wire that connects to Z53 pin 12 on the CPU board and connecting it to Z37 pin 1 instead If you do not wish to make this change to your speedup board the following patch may also eliminate your bootup problems FASTBOOT FIX Apply with the command PATCH BOOT SYS WOLVES USING FASTBOOT D00 BD DF DF DF DF D00 CB DF DF End of patch Use the BUILD command to create a file containing the above patch and then use the indicated command to apply the patch to each of your system disks NOT to your master The patch is not carried over when you do a backup so you will have to reapply it to every system disk you create This is strictly an optional patch and it will not be made an official part of the LDOS system It does appear to work quite well nevertheless In the last few paragraphs you probably noticed that I q
11. is on LDOS doubles the length of the delay loop used when a disk drive motor is started The other two problems mentioned above do not occur under LDOS at all since it bases its index hole detection on the system s 25 ms heartbeat counter instead of a delay loop and the delay loop used to allow for settling time is already long enough to work at the fast speed without change When you do a SYSTEM SYSGEN the state of the fast clock bit is saved in your CONFIG file and the proper value is output to port X FE after the CONFIG file has been loaded in Despite the careful provisions that have been made for handling clock speedups in LDOS there are still some problems that can crop up The most common complaint is that SYSTEM FAST seems to cause a SYSTEM CRASH If you have a Radio Shack expansion interface the usual reason for this is flakey memory in the interface The memory seems to run fine at 1 774 MHz but you get random bit errors when you switch to the higher speed which cause any device drivers that may be in high memory to crash causing a reboot or system lockup If this is your problem you will probably notice that SYSTEM FAST works fine if you boot up without a CONFIG file hold down the CLEAR gt key while booting It is also possible that the Z 80 CPU in your keyboard will not function at the higher speed as the Z 80 s used by Radio Shack are only guaranteed to run at 2 5 MHz or below Again if you have a Radio Shack
12. means of a bit value in the write sector FDC command It is detected by a specific pattern in the status register of the FDC which is read by the CPU When Western Digital was designing the 1771 chip they had an unused bit position in the write sector command byte Now if two DAMs are good then four DAMs are better or so they thought WD defined X F9 and X FA generating the four DAMs via a two bit pattern Page 5 00 gt X FB 01 gt X FA 10 gt X F9 11 gt X F8 So far so good The original design of TRSDOS made use of two of the above DAMs In order to be able to differentiate a system sector i e any one of the sectors constituting the directory from an ordinary sector system sectors are written with an X FA DAM while all other sectors are written with an X FB DAM In reading any sector by checking the status register of the FDC the operating system can determine if the sector just read was in the directory or not Before we get far down the road it is best to clarify a printing error in the WD data sheet for the 1771 The DAM status bit configuration is as follows and NOT what appears on the WD data sheet Pay close attention to the revised column headings that was the error Status bit 6 Status bit 5 Data AM 0 0 FB 0 1 FA 1 0 F9 1 1 F8 The plot thickens when double density enters the scene The 179X series of FDC chips support the transfer of double density data which certainly helps to increase the
13. recently accessed record of a random file which is currently open The syntax for this function is LOC n where n is the buffer number corresponding to the file If the LOC function is used and the buffer number specified does not relate to an open file the error message BAD FILE NUMBER will appear 3 If the LBASIC command OPEN EO is given but the file specified does not exist a FILE NOT FOUND error message will be generated 4 Any LBASIC program may be protected with an Execute Only password This protection status is assigned using the ATTRIB Library command What this means is that the protected program may be RUN but any attempt to LOAD LIST LLIST or examine the program will not be allowed If an attempt is made to break the program during execution the program will be erased from memory Finally the DEBUGger will be disabled during the execution of a protected program 5 If you use the comma EDIT or the period LIST abbreviations these characters must be the FIRST character entered in a line for the command to be issued For example suppose you finish entering a program line type ina line number and realize that the line you have just entered needs to be edited If you backspace to erase the new line number and press lt gt you will NOT be placed in the Edit mode The comma was not the FIRST character to be entered in the line as a line number and backspace characters were entered Using the ab
14. routine please do NOT call the LDOS Support Center for assistance as you will definitely have difficulty in other aspects of LINKER s use and we cannot operate as a training center Good luck to the experimenters 00100 LINKER ASM Roy Soltoff 00110 00120 On entry to this routine an LDOS command line 00130 should be located in a buffer area The address 00140 of the buffer should be contained in a word 00150 labeled CMDPTR The routine should be entered 00160 by a CALL LDOSCMD instruction The following 00170 code is assembled with your program 00180 00190 LDOSCMD LD HL EXIT point to EXIT amp ABORT 00200 PUSH HL save pointer 00210 LD DE LDOSSV point to our save area 00220 LD BC 6 init to move 6 bytes 00230 PUSH BC save count 00240 LDIR save EXIT amp ABORT 00250 LD HL NEWVECS point to new vectors 00260 POP BC recover 6 count Page 12 00270 POP DE point DE to EXIT 00280 LDIR move in new vectors 00290 LD HL HIGHS p u high memory ptr 00300 LD HIGHSV HL amp save it 00310 LD HL NEWHIGH this value would be 00320 LD HIGHS HL below our program 00330 LD HL CMDPTR pt to command string 00340 LD SAVSP SP save our stack pointer 00350 JP CMNDI let LDOS interpret it 00360 LDOSRET LD HL LDOSSV pt to saved vectors 00370 LD DE EXIT 00380 LD BC 6 move the saved vectors 00390 LDIR back into EXIT amp ABORT 00400 LD HL 0 p u saved HIGHS 00410 HIGHSV
15. storage capacity of disk drives This was not done at the sacrifice of single density WD used an external input to the 1791 chip to control the switching between single and double density But at the same time WD wanted to add other features including the ability to check whether the correct head had been selected when reading from a two sided disk drive This required additional bits in the read and write sector commands Where did these bits come from One bit was taken from the two used to denote the DAM This results in the selection of only two distinct DAMs You guessed it The 179X can generate only an X F8 or an X FB when writing and furthermore it CANNOT differentiate between an X FB and X FA when reading returning a 0 status for both or between an X F9 and X F8 returning a 1 status for both in bit position 5 of the status byte Essentially if you examine the above table the FDC 179X series returns in status bit 5 what was returned in status bit 6 of the 1771 while status bit 6 of the 179X is unused Since the 1771 data sheet always had columns 5 and 6 reversed this change appears more than coincidental and I suspect that Western Digital engineers were the victims of an error in their own data sheet Consider a diskette made on a system with a 1771 like the TRS 80 Put the diskette on a Model III which uses a 179X series FDC and the DOS cannot find the directory because the FDC doesn t know that the X FA is any diff
16. update notifying owners documenting changes performing duplication and returning your master disk we will not be making a profit on it The original fee or 1 00 was set up because a hardware company LOBO Drives was subsidizing the costs This is no longer the case and the charge had to be raised to 5 00 Page 1 You may disagree with this new fee but we can not perform services at a loss Tandy Apparat DOS Ultrados and all other vendors known to us do not correct problems or release enhanced versions as fast or as often as we do We consider this to be one or our most important selling points But we can t continue doing so if we lose money every time we try to give you a better software package we d go out or business You may think that we should have made plenty of money when we sold LDOS to you at 149 00 and that would be correct But in most cases we did not receive anywhere near the retail price from you The vast majority of LDOS s are sold through dealers and are substantially discounted to them Many hundreds of you paid only 40 00 to receive an LDOS as a vTos 4 0 replacement LDOS costs about 30 00 per package to produce with royalties printing binders disk duplicating mailer packaging and handling To amortize the actual cost of development and enhancement we have to sell over 5000 LDOS s per year just to break even Authoring the LDOS manual alone cost over 25 000 LDOS owners should realize that this i
17. x The double density disk format used by Percom s DBLDOS is NOT compatible with LDOS The LDOS double density format is the same in all versions of LDOS Model I with the Doubler Model I with the Lobo LX 80 and Model III It could not be changed to match DBLDOS 05 06 50 44 55 42 4C 20 01 02 00 52 21 5A 52 CD 67 44 DD 21 C4 52 2A 49 40 11 9D 54 B7 ED 52 44 4D 3E 18 DD 6E 00 DD 66 01 23 5E 23 56 EB 09 EB 72 2B 73 DD 23 DD 23 3D 20 E9 ED 5B 49 40 21 9D 54 01 AA 01 ED B8 ED 53 49 40 13 EB FD 21 00 47 06 04 11 OA 00 FD 75 01 FD 74 02 FD CB 04 F6 FD 19 10 F2 C3 2D 40 50 44 55 42 4C 20 2D 20 44 72 69 76 65 72 20 66 6F 72 20 74 68 65 20 50 65 72 63 6F 6D 20 44 6F 75 62 6C 65 72 20 49 49 20 2D 20 56 65 72 73 69 6F 6E 20 54 45 53 54 31 OA 43 6F 70 79 72 69 67 68 74 20 28 63 29 20 31 39 38 31 2C 20 4C 6F 67 69 63 61 6C 20 53 79 73 74 65 6D 73 20 49 6E 63 6F 72 70 6F 72 61 74 65 64 OD 2F 53 01 53 4B 53 65 53 8E 53 AO 53 A3 53 B7 53 CF 53 D8 53 DF 53 E6 53 F1 53 OD 54 19 54 2E 54 33 54 01 54 10 53 5A 54 98 54 BD 53 9B 54 7C 53 3A OF 43 CB 5F 28 12 DB FE CB 87 D3 01 02 00 53 FE CD OD 53 F5 DB FE CB C7 D3 FE F1 C9 78 CB 58 C2 AO 53 FE 07 28 40 FE 06 28 4A 3D 28 11 FD 34 05 FE 04 06 58 28 67 FD 36 05 00 06 08 18 5F CD 57 53 07 F5 FD 7E 03 E6 10 OF FD B6 04 E6 OF 32 09 43 32 El 37 F1 DO FD CB 03 56 CC 4E 53 C5 01 00 7F CD 60 00 C1 C9 3A EC 37 CB 47 C8 3A 09 43 32 El 37 18 F2 CD 57 53 FD 7E 05 32 ED 37 FD 7E 07 E6 1F 3C FD CB 03 A6 93 ED 44 D5 FA 84 53 FD CB 03 E6 5
18. 2 6F 64 75 63 74 69 6F 6E 20 70 65 72 72 20 70 65 72 73 6F 6E 61 6C 20 75 73 65 20 6F 6E 5A 00 53 6D 65 74 65 72 20 65 72 72 6F 72 OD 44 65 61 63 74 69 76 65 OD 4E 6F 74 20 61 6E 20 69 6E 70 OD 44 65 76 69 63 65 20 69 73 20 72 6F 75 74 65 64 00 00 F5 3A 80 38 E6 10 28 05 F1 E6 9F 37 C9 F1 C9 This printer filter program will allow the MX 80 printer to directly print TRS 80 graphics with the JKL GRAPHIC parameter It was contributed by Ken Roser 05 2A DD 4D 20 20 OA 6C 74 73 79 00 06 49 75 58 34 73 73 65 61 20 21 52 4D 40 01 2D 2F 68 6F 20 6E 66 OD BEEP FLT 58 01 DD 38 31 69 20 77 64 69 38 38 11 74 30 31 66 74 69 61 6C 0C 30 00 02 20 2F 74 68 74 72 74 79 2F AF EB 46 38 20 61 68 64 65 FE This keyboard filter a key is 05 52 53 72 52 69 06 FE 2A 02 18 6F 42 10 49 c3 EB 20 pressed It 45 CA 40 2D 42 66 45 50 2F 5A 52 CB 40 21 BB 46 ED 21 49 31 54 74 20 20 72 co 01 42 F7 4c OA 52 20 74 63 20 30 82 00 52 1A E6 02 28 33 D5 21 41 52 CD 67 44 DD El 22 49 40 23 DD 7E 01 32 06 53 DD 7E 02 32 07 53 F3 52 ED BO FB C3 2D 40 21 D7 52 CD 7B 44 C3 30 40 OA 54 45 52 20 2D 20 4B 65 6E 20 52 6F 73 65 72 20 2D OA 54 68 69 73 20 66 69 6C 74 65 72 20 77 69 6C 6C 53 01 82 80 52 2D 38 30 20 67 72 61 70 68 69 63 73 74 68 65 79 20 61 72 65 20 63 6F 6D 70 61 74 69 62 68 65 20 4D 58 2D 38 30 OA 69 6E 20 74 68 65
19. 20 73 6F 6E 66 69 67 75 72 61 74 69 6F 6E 2E OD 54 68 69 69 73 20 66 6F 72 20 6F 75 74 70 75 74 20 6F 6E 6C 07 FE 80 01 OA 00 53 38 03 C6 20 4F C3 00 00 02 02 will output a beep tone to the cassette port each time was contributed by Tim Mann 46 01 02 00 52 D5 1A F5 21 5F 52 CD 67 44 F1 FE 08 CA 50 47 CA 55 52 DD El DD E5 DD 6E 01 DD 66 02 22 03 53 22 06 01 31 00 AF ED 42 22 49 40 23 EB 21 02 53 D5 ED BO D1 DD 73 01 DD 52 CD 7B 44 C3 30 40 21 CB 52 18 F5 21 DD 52 18 FO 21 F1 45 45 50 2F 46 4C 54 20 2D 20 4B 65 79 62 6F 61 72 64 20 61 75 64 65 65 64 62 61 63 6B 20 66 69 6C 74 65 72 OA 43 6F 70 79 72 69 67 Page 22 68 6E 20 6F 69 32 D3 UPD 74 20 28 63 29 20 31 39 38 31 20 54 69 6D 6F 74 68 79 20 50 2E 20 4D 61 6E 20 2D 20 56 65 72 73 69 6F 6E 20 31 2E 30 OA OD 50 61 72 61 6D 65 74 65 72 65 72 72 6F 72 OD 44 65 76 69 63 65 20 6E 6F 74 20 61 63 74 69 76 65 OD 4E 74 20 61 6E 20 69 6E 70 75 74 20 64 65 76 69 63 65 OD 44 65 76 69 63 65 20 73 20 72 6F 75 74 65 01 35 00 53 64 OD D2 00 00 CD 00 00 C8 D5 C5 F5 3E 01 E4 37 06 05 16 OF 3A OF 43 CB 5F 28 04 CB 20 CB 22 3A 3D 40 F6 01 4A EE 03 FF 0D 20 FD 10 F6 F1 Cl D1 C9 02 02 00 52 ATE BAS This LBasic program will allow you to update your LDOS working disks after you have sent in your Master disk for an update It will copy only those programs which already exist on the working disk It was contributed by Tim Man 10 20 30 40 50 55 60 70 100 110 120 130 133
20. 8 04 F1 CB AF C9 F1 C9 02 02 00 52 PERCOM DOUBLER DRIVER PDUBL CMD The disk driver program PDUBL is provided to allow you to use the Percom Doubler II double density modification with LDOS Page 24 This command loads a special disk driver program which allows you to use the Percom Doubler II to read write and format double density disks If you have a Doubler installed after you give this command you can use either single or double density disks in any of your 5 disk drives LDOS will automatically recognize whether you have a single or double density diskette in a drive and react accordingly PDUBL also includes support for double sided 5 drives on a Radio Shack expansion interface with the Doubler Both sides of the diskette are treated as a single volume The drives and cabling must be set up correctly for this feature to work The PDUBL driver is loaded into high memory and protected by lowering HIGHS Logical drives 0 3 are set up to use this driver in place of the normal LDOS Single density driver Under LDOS 5 0 2 or later you can use the SYSTEM SYSGEN command to save the driver in your configuration file to be loaded automatically every time you boot Please note that you CANNOT boot up on a double density LDOS diskette when using the Percom Doubler You may however boot up on a single density diskette and exchange it for a double density diskette as soon as the bootstrap operation has finished WARNING
21. DC and status information returned to the CPU from the FDC The 1771 is compatible only with soft sector formatted media In this type of diskette operation the location of the space occupied by a sector is denoted by special data patterns and identification fields written on the diskette during a formatting operation This is in contrast to hard sectored media which has a physical sense hole on the outer or inner rim of the diskette to mark the physical beginning of each sector The soft sectored format was defined by IBM with the introduction of eight inch disk drives A variation of this format is used in the TRS 80 Without going into too much detail on the exact format suffice to say that it consists essentially of an index mark track and sector identification a data address mark a sector of data and checksum fields actually called cyclical redundancy checks CRC s This information exists for every sector on the diskette There is also dead space called gaps between the sectors The dead space is used by the FDC as a buffer zone to aid in separating the end of one sector from the identification field of the next The data address mark was defined by IBM to be one of two values an X FB used to indicate that the respective sector contains data or an X F8 used to indicate that the data in the sector was deleted The value of the DAM is controlled on writing not as a discrete byte of information passed to the FDC but rather by
22. DOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS S LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDO OS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LD DOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS L LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS THE LDOS QUARTERLY July 1 1981 Volume 1 Number 1 THE LDOS QUARTERLY July 1 1981 Volume 1 Number 1 ANNOUNCING PERCOM DOUBLER SUPPORT SEE THE UPDATE NEWS FOR DETAILS The Percom Doubler II seems to be working well and will be supported by LDOS effective June 15 1981 This does not mean we are supporting the Doubler I the LNW Doubler or any other doubler that claims to be software compatible Although our software may run these other doublers it was designed and tested only on the Percom Doubler II If you use another doubler and experience problems don t call us call the manufacturer of your doubler Along with the Doubler II support will be double sided support on the RS interface Only three drives may be used with this double sided support because the Expansion Interface uses the side select line for drive select 4 Also a cable without pins missing is required and all drives to be used must have the ability to be set int
23. DOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS L LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS S LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDO OS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LD DOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS L LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS S LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDO OS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LD DOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS L LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS S LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDO OS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LD DOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS L LDOS LDOS LDOS LDOS LDOS LDOS L
24. F ED 53 EE 37 D1 FD 72 05 06 18 CD 2F 53 FD 7E 03 E6 03 BO 32 EC 37 06 08 10 FE AF C9 CD 57 53 CD 6C 54 78 CB 50 06 06 20 16 06 04 OE 88 FE OA 28 08 06 OA CD D5 53 01 1A 02 CD D5 53 01 1A 7E OE A8 FE OE 38 06 OE F4 20 02 OE A9 CD D5 53 09 12 OA E3 7E 23 32 65 54 7E 23 66 6F 22 29 54 El C5 CB 61 CC 65 53 D5 E5 21 EC 37 11 EF 37 CD 57 53 79 FE A9 20 08 FD CB 03 76 20 02 3E 01 A3 00 54 AB CD 97 53 CB 69 C1 C5 20 OA 7E E6 03 E2 OA 54 F3 1A 18 16 FB F3 7E E6 F6 CA 14 54 OA 12 CB 46 28 24 03 OA 03 CB 4E 28 FC 00 00 03 CB 4E C2 29 54 CB 4E C2 29 54 CB 4E 20 EF CB 4E 20 EB CB 4E 20 E7 CB 46 20 E6 FB 7E E6 7C El D1 C1 C8 CB 57 20 91 F5 E6 18 28 OB CB 67 C5 C4 7E 54 C1 F1 10 82 06 F1 47 3E 00 CB 08 D8 3C 18 FA FD 7E 03 E6 40 07 07 F6 FE 32 EC 37 3E DO 32 EC 37 C9 E5 FD 7E 03 EE 40 FD 77 03 21 09 24 CB 77 28 03 21 11 45 FD 75 07 FD 74 08 El CD 6C 54 C3 27 53 56 33 39 02 02 00 52 Page 25 DCAL BAS This program will allow you to check your disk drive motor speed It runs only on the Radio Shack expansion interface Contributed by Tim Mann 10 REM DISK DRIVE TIMING PROGRAM 20 REM TIM MANN 30 GOSUB 8000 LOAD MACHINE LANGUAGE ROUTINE 40 OUT 254 0 ENSURE CLOCK SET TO 1 774 MHZ 50 CLS PRINT PRINT TRS 80 DISK DRIVE SPEED CALIBRATION PROGRAM 60 PRINT INSERT A DISK IN THE DRIVE TO BE CALIBRATED PRINT 70 INPUT DRIVE NUMBER 0 3 DR 80 IF DR lt 0 OR DR gt 3 OR DR lt gt INT DR THEN 70 90 DR 2 DR 100 DEF USR1 amp H900C 110 FOR I 1 TO 100 START DRI
25. LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS S LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDO OS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LD DOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS L LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS S LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDO OS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LD DOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS L LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS S LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDO OS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LD DOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS L LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS LDOS S LDOS LDO S
26. LOOR section the hours on the 800 lines are being changed The new hours will be from 10AM to 12 NOON and from 4PM to 6PM Central time We have been receiving many calls from people who have not read the manual and call for answers to questions that are explained in detail in the manual Please DO NOT call until you have looked in the manual for an answer to your question Customer Support needs to know what LDOS version and hardware you have if they are to help you That means you MUST have your serial number in hand when making the call The procedure that we use is Page 7 1 Verify the name and serial number from our list of owners and check the version number We can immediately tell what version you have by the list If we have a more recent update version we can inform you of it 2 Starting immediately if you don t have your serial number when you call you will be told to call back when you have it We can t help you if we have incomplete information 3 Only those owners whose registration cards are received will be allowed to update their disks use the MicroNET bulletin board and receive the newsletter It is extremely difficult to mail update notices and newsletters to unknown owners We will try to answer any questions you may have about the operating system features and commands However certain types of questions are impossible for us to answer PLEASE DO NOT CALL AND ASK IF A CERTAIN PROGRAM WILL RUN ON THE LD
27. NT 2 GOTO 450 PRINT 2 CLOSE PRINT PRINT Done PRINT GOTO 100 00 DEF FNH1 X MIDS 0123456789ABCDEF X AND 15 1 1 10 DEF FNH2 X FNH1S X 16 FNH1S X 40 DEF FND1 X INSTR 123456789ABCDEF LEFTS X 1 50 DEF FND2 X FND1 RIGHTS X 1 16 FND1 RIGHTS XS 2 70 RETURN 00 END Page 21 Hex to Binary PENCTL FLT This keyboard filter program will allow Electric Pencil owners to use the LDOS keyboard driver and the original Pencil control key This program was contributed 05 52 53 72 53 61 79 20 72 6D 6C 76 75 0D 06 FE 2A 02 18 63 20 31 73 69 79 69 74 D2 50 10 49 c3 EB 74 75 39 69 74 OA 63 20 00 MX80 FLT 45 CA 40 2D 50 69 6E 38 6F 74 OD 65 64 00 by 4E 5A 01 40 45 76 64 31 6E 65 50 20 65 CD Tim Mann 43 52 15 21 4E 61 65 20 20 64 61 6E 76 54 CB 00 FC 43 74 72 54 31 20 72 6F 69 4c 47 AF 52 54 65 20 69 2E 66 61 74 63 01 CA ED CD 4C 20 4C 6D 30 6F 01 20 65 02 00 52 D5 1A F5 21 5F 52 CD 67 44 F1 FE 08 CA 50 55 52 DD El DD E5 DD 6E 01 DD 66 02 22 44 53 22 47 42 22 49 40 23 EB 21 43 53 D5 ED BO D1 DD 73 01 DD 7B 44 C3 30 40 21 OC 53 18 F5 21 1E 53 18 FO 21 32 2F 46 4C 54 20 2D 20 46 69 6C 74 65 72 20 74 6F 20 50 65 6E 63 69 6C 20 63 6F 6E 74 72 6F 6C 20 6B 65 44 4F 53 OA 43 6F 70 79 72 69 67 68 74 20 28 63 29 6F 74 68 79 20 50 2E 20 4D 61 6E 6E 20 2D 20 56 65 OA 52 65 70 7
28. OS SYSTEM we have not tested any programs other than Electric Pencil and Scripsit The only answer we can give you is try it and see Your best bet would be to call the software vendor or the author Technical questions that cannot be answered using information in the user s manual probably cannot be answered directly on the 800 line We will try to answer any questions immediately but if finding the answer would entail searching the source code or talking with an LDOS systems analyst the following rules will apply 1 Detailed technical questions may be answered over the phone by our system s analyst if an appointment is made in advance The fee for phone time is 50 00 per hour 1 hour minimum with the user initiating the call 2 Technical questions submitted in writing will be answered free of charge as long as they do not entail large amounts of research or detailed explanation However any technical questions no matter how complex will be fully answered for a fee that will be dependent on the nature of the questions In other words we will answer any questions about any part of the LDOS operating system but like any other service compensation will be required for questions outside of the normal user support Please do not call in with suggestions for new features or enhancements to LDOS Leave us a note on the bulletin board or send us a letter Making suggestions by phone ties up the line for those who have need of our serv
29. Send signal is received before sending a character If CD is turned ON the driver will wait until a Carrier Detect signal is present before sending a character If DSR is turned on the absence of the Data Set Ready signal will cause the driver to wait Radio Shack interface only In the example using the RS232L driver the Port 1 should be changed to Port 0 JOB CONTROL LANGUAGE Page 1 paragraph 2 should end with the sentence Also no line in a JCL can exceed 64 characters in length Page 18 Page 2 first paragraph in the JCL USED WITH LBASIC section should note that only those commands that do not alter high memory can be in a JCL used from LBASIC Page 4 paragraph 4 describes the logical operators available with JCL When using these operators no space should be left between the operator sign and the token LBASIC See the LBASIC section of the newsletter Section DCT 3 bit 4 had page formatting problems The correct text is A 1 will cause the selection of the disk s second side The first side will be selected if this bit is a 0 The bit value will match the side indicator bit in the sector header as written by the FDC Section DCT 9 last paragraph second sentence The highest numbered cylinder should read highest numbered sector TECH INFO lt DIRECTORY RECORDS gt PAGES 7 11 Page 7 GAT X CD last sentence should read Bits 2 0 contain the number of granules per cylinder 1 Page
30. VE 120 POKE amp H37E1 DR 130 NEXT I 140 POKE amp H37EC 3 RESTORE COMMAND 150 FOR 1 1 TO 100 NEXT 160 A USR1 DR 170 CT PEEK amp H9092 256 PEEK amp H9093 180 RPM 60 1 774E6 CT 35 112 190 IF SBAR 0 THEN SBAR RPM 200 SBAR SBAR 9 RPM 1 210 PRINT USING SPEED SMOOTHED SPEED RPM SBAR 220 GOTO 160 8000 REM LOAD MACHINE LANGUAGE ROUTINE 8010 FOR I amp H900C TO amp H9047 8020 READ B POKE I B NEXT I RETURN 9000 DATA 205 127 10 125 243 237 115 128 144 17 9010 DATA 225 55 221 33 144 144 6 2 49 0 9020 DATA 0 33 236 55 18 203 78 51 202 36 9030 DATA 144 18 203 78 51 194 43 144 33 0 9040 DATA 0 57 221 117 0 221 35 221 116 0 9050 DATA 221 35 16 220 237 123 128 144 251 201 The addresses of the contributing people are Tim Mann Chuck Jensen Ken Roser 4139 N 78th Ct 4869 N 71st St 1907 Arbor Lane Milwaukee WI 53222 Milwaukee WI 53218 Union NJ 07083 Thus ends the LDOS QUARTERLY for July of 1981 This publication is of course copyrighted Reproduction for other than personal use will be treated as a violation of Federal copyright laws our attorneys WILL prosecute and have been instructed to seek the death penalty TRS 80 is a trademark of Radio Shack a Tandy corporation company Page 26
31. does NOT create parity errors it only reports them A parity error is the sole creation of the Floppy Disk Controller FOC chip in whichever expansion interface you are using When the FDC formats a disk it writes CRC bytes to use as a checksum for the sector ID s and the data written to the sectors When the FDC reads data from a disk sector it computes a checksum for that data and compares it to the CRC that was created when the data was written to that sector If there is a difference the FDC returns a CRC error to the operating system and Parity error during read appears on the screen When attempting a write if the FDC detects a difference in the Sector ID checksum and its CRC a Parity error during write message will appear Now for the next obvious question Why does my system get parity errors Well The only reason for the parity error message is a CRC error from the FDC If a poor data separator circuit is causing incorrect data to be read from the disk an error occurs If the disk heads are dirty the data written to the disk may not have sufficient amplitude when read back and an error occurs Some drives have internal adjustments that control data pulse timing If they are out or tolerance an error occurs All disk media is not created equal using marginal media produces marginal results especially with double density What it all boils down to is that a parity error means something is not quite right with th
32. e that all variables are recognized in a cross reference listing proper punctuation must be used 10 When using CMD X or CMD N the line number associated with the RUN command i e RUN400 and the ERL command will be ignored That is to say if the CMD X command is given line numbers used with the RUN and ERL commands will not be displayed in the cross reference listing If the CMD N command is given line numbers used with the RUN and ERL commands will not be updated and thus may not be correct 11 Default values for the parameters in the CMD N command are as follows aaaa 1 bbbb 20 cccc 20 dddd 65529 12 There may have been some confusion as to what the last parameter in the CMD N command represents i e dddd The following two paragraphs will try to explain how this parameter is to be used Suppose you have a program whose beginning line number is 10 and whose ending line number is 2000 In addition you have a block of code within your program that you wish to renumber and the line numbers in this block range from 600 to 800 The next line number in your program following line number 800 is 1350 After renumbering takes place line 800 will be reassigned the line number 1260 A correct value for the last parameter would be a number which is between 1261 and 1349 NOT 800 That is to say the last parameter must always be greater than the value of the last line number in the block to be renumbered AFTER renumbering occurs
33. e hardware or media Page 4 The data sheets on the Western Digital 1771 and 179x series FDC chips contain more information on the use of the CRC bytes and what sequence of events will cause a CRC error Everything you always wanted to know about Data Address Marks those damn DAMs and other assorted trivia by Roy Soltoff This issue s technical topic concerns itself with a subject destined to become one of the hottest tidbits of thingamajigs scroillions and zwortjhinks of recent fame beat out only by the delectable doubler debacle This DAM topic covers the least understood principle of operation in the TRS 80 operating systems and is associated with the ubiquitous Floppy Disk Controller Since you are an avid reader of this newsletter you must be using LDOS unless you snuck a copy of the NL and now wish you were using LDOS One thing required of all disk operating system users is that they have an expansion interface which IS used for a little more than a means of interconnecting five cables in a junction box The E I as it is commonly known contains the FDC which is used to interface the operating system with the disk drives The FDC used in the TRS 80 is manufactured by Western Digital This Large Scale Integrated LSI chip a 1771 handles all serial data transfer to and from the diskette converting parallel data between it and the CPU The CPU controls and handshakes with the FDC via commands and data values passed to the F
34. erent than an X FB It can t tell them apart This is the main reason why the Percom Doubler for the Model I uses both a 1771 and a 1791 FDC chip so that its single density operation would be compatible with other TRS 80s Otherwise your disk could not be used easily by other systems nor could you read diskettes made on other systems What would be required would be to have a utility to regenerate the proper data address mark for your system on the diskette This is quite easy to do but would be cumbersome There is another solution Page 6 Since the 1771 can both generate and detect an X F8 DAM LDOS for the Model I actually doesn t care whether the DAM used in the system sectors is an X FA or X F8 either is acceptable because LDOS ignores bit 6 of the status Thus an X F9 is equivalent to an X FB and an X F8 is equivalent to an X FA TRSDOS and possibly other DOSs do not ignore bit 6 but would suspect that some unknown disk error occurred if it read a sector preceded by an X F8 or X F9 For this reason up to this time LDOS has generated an X FA for the directory sectors Other systems however are already using 179X FDCs The double density modifications for the Model I use 1791s The LX 80 E I uses a 1791 The Model III uses a 1793 equivalent to the 1791 In order to be able to exchange media between these machine configurations and the stock Model I it would make sense to have all machines accept each other s DAMs The
35. ernally to a specific physical drive number If the above two new features are not enough we have made other major modifications to the system The RS 232 driver and other drivers that need to be initialized may now be SYSGENed and will reinitialize themselves on each boot up Revised RS 232 drivers are included in this release File space allocation is now more random and several small bugs have been cured This new version of LDOS is designated 5 0 2 and will be ready for shipment around June 15th It will come complete with explanatory documentation and manual inserts Note All updates will be returned in a disk mailer If you send us a library case a shoe box or a refrigerator box you will still get only a disk mailer back The ownership of the rights to LDOS has changed hands LDOS is now owned by Logical Systems Inc LSI 11520 N Port Washington Rd Mequon Wisconsin 53092 LSI is a new company formed to develop manage market and support the LDOS product line LSI is a Wisconsin Corporation the principals of which are those originally involved with the creation of LDOS Some changes were needed in company policy because of this new arrangement The most unpleasant is that updates to the LDOS product 5 x x will now be 5 00 and there will be no exceptions This is required due to the costs of clerical work repackaging mailing and the update itself This new update fee will just cover the actual costs of creating the
36. fferent PACK ID S disk name and master password or the XFER will abort UTILITY lt BACKUP gt PAGE 1 The X parameter is only valid for backups with drive 0 as the source drive Backup X and single drive backups cannot be included in a JCL file Page 17 UTILITY lt FORMAT gt PAGE 3 In the section on double sided formatting note that either a special driver routine or a hardware modification will be necessary to use a double sided drive as a single drive on the Radio Shack expansion interface UTILITY lt LCOMM gt PAGES 2 6 The KI device control on page 2 should say lt CLR gt lt 1 gt rather than lt CLR gt lt 6 gt lt 1 gt The PEOF on page 6 should read lt CLR gt lt SH gt lt 6 gt The lt CLR gt lt amp gt shown is in effect the same thing but does not follow the format used for the other control functions UTILITY lt PATCH gt PAGE 4 The command line patch example PATCH MONITOR CMD should have parentheses around the text X E100 C3 66 00 CD 03 40 The parentheses must be used in all command line patches DEVICE DRIVER lt RS232 RS232L gt PAGES 1 2 On page 1 the PORT command for LOBO LX 80 owners should show PORT 0 for serial port A and PORT 1 for serial port B On page 2 the default parameters for the LX 80 should show PORT 0 The fourth paragraph describes Line Condition parameters The correct description is as follows If CTS is turned ON the driver will wait until a Clear To
37. ices Please do not interpret this section and the shortening of 800 service hours to mean a decrease in the quality of the customer support We will continue to cheerfully provide operating help and system explanations to all of our registered owners What we hope to accomplish is an optimization of our 800 line service and new feature product development time Remember the Support personnel are the same people who create test and document all of the enhancements to the LDOS family of products Page 8 NOTES ON LBASIC In the first edition of the manual there were several points that were left out and several points which needed clarification concerning LBASIC and its features In this section of the newsletter we will try to clear up some of these areas 1 Although it is not stated in the manual the LDOS command LBASIC does exist and does work The user is warned NOT to perform any commands that may affect HIGHS or alter any memory above X 6000 if he wishes to use LBASIC to reenter LBASIC Doing so may cause the destruction of any LBASIC program that is in memory It is much safer and wiser to perform any LDOS commands or functions from LBASIC using the CMD command format Also at this time LBASIC will NOT work with the LX80 interface after the system has been rebooted However LBASIC will work with the LX80 interface after a CMD S command has been issued 2 The LBASIC function LOC will return the most
38. interface you may have difficulty in booting The usual symptom is that the system boots fine on power up but using the Reset button or the BOOT command after the fast clock has been turned on causes a DISK ERROR or SYS ERROR message or a crash during the bootstrap procedure The reason for this appears to be that the system boot loader BOOT SYS does not delay quite long enough after passing the disk controller a read command to allow for a clock speed of 3 54 MHz If you are having this problem there are two solutions open to you You can modify your clock speedup board to reset itself to the slower speed whenever you boot up allowing it to be switched back in by your CONFIG file or you can patch BOOT SYS to provide an increased time delay On my own system I found it more satisfactory to make the hardware modification but I will explain both methods here and let you take your choice In my own system I have the Archbold speedup board which seems to be the most popular one The version of the board I have is an older one which is no longer being made but there were quite a few of this type sold Mounted on the board are a resistor and capacitor that form a power up reset circuit Page 14 This automatically resets the board to the slow speed when you turn on the power to the keyboard The modification I use is very simple Remove the resistor and capacitor from the board by cutting their leads on the component side Then run a wire from
39. land or the Common Market Countries should send their master disk with 10 00 to MOLIMERX at LDOS Support c o MOLIMERX Ltd 1 Buckhurst Rd Bexhill Sussex England Phone 0424 223636 Note If you are sending to Molimerx for an update make your check payable to Molimerx Ltd Page 2 Molimerx is our distributor in England and Western Europe and will be providing update services and customer support They have our full support and we maintain very close communications with them For any of you that may be able to help we are actively seeking a distributor to represent us in Japan If you can recommend a firm please let us know LSI is happy to announce the release of LDOS 5 0 2 This update version will be available June 15th Among the enhancements is double density support for the Percom Doubler II As with the original maintenance release changes made to the operating system will be detailed in the sheets that are returned with your updated Master disk To get the update send in your disk with the 5 00 fee The address is in the customer service section of the manual If you don t want to wait for your 5 0 2 disk to arrive you can find the object code for the Doubler driver in our MicroNET database and in the program section of this newsletter You can download it and convert it with BINHEX BAS found in the database and also reprinted in this newsletter Note Checks or money orders for all updates should be made out to
40. mand interpreter This function is activated via the CMNDI system call noted on page 1 of the Tech Info Entry Points Control part of the LDOS reference manual The CMNDI vector is similar to the EXIT vector in that it returns to LDOS Ready It is different in that it passes LDOS a command line to be interpreted and executed prior to the LDOS Ready prompt In some cases this can be quite useful In other cases it would be desirable to return to the running application after the command is executed rather than exiting to the LDOS Ready prompt This can be accomplished by specific code in the assembler program once certain limitations are understood First the CMNDI processor can execute ANY command that could be entered in response to LDOS Ready That includes all LDOS library commands all LDOS utilities and all other user CMD files If you want the system to return to your program you will have to ensure that the command being executed will not clobber your program As a general rule of thumb by restricting your application to a memory region above X 6000 all LDOS library commands can be accessed You are on your own when it comes to CMD files An experienced Assembler programmer should be able to make sense out of the LINKER routine shown below This routine if included in your program will enable the program to access the CMNDI interpreter while providing linkage code back to the program If you do NOT understand the LINKER
41. n diskettes would be directly usable on each machine This would result in less confusion and frustration and improve tremendously the operating convenience of users dealing with multiple systems The bottom line is that effective with release 5 0 2 LDOS will generate only the X FB and X F8 data address marks although it will still be able to read disks written with X FA data address marks when the disk controller is a 1771 As time permits we will try to provide patches to other operating systems so that they will also be able to use X FB and X F8 All that is required is to have the DOS mask and ignore status bit 6 on sector reads and write an xX F8 data address mark on directory sector writes The modifications are simple to implement and will result in a more powerful and convenient operation for all We trust that our users will be understanding of this need and appreciative for our willingness to discuss this problem with you This is being written almost exactly 3 months after the first LDOS 5 0 was sent out into the world Since that time we have taken what seems like a year s worth of calls on our LDOS Support 800 lines On a busy day our customer service department will deal with over 100 people via updates registrations and phone calls Although there is a section in the manual that deals with when and how to use the 800 number it seems that more will need to be said about it here As stated in the VIEW FROM THE BOTTOM F
42. n enter in the following string 010700523E0CC33B0002020052 The byte OC is the actual character sent and could be changed to some other control character to perform other printer functions An interesting feature not documented in the manual concerns the system s type ahead feature and the SYSTEM SYSGEN command When doing a SYSGEN with type ahead on anything you type on the keyboard up to the time the User configuration built message appears on the screen will be saved in the configuration file and executed each time the system is powered up or booted If you don t want this to happen don t type ahead when the SYSGEN is occurring Some of you have indicated that you dislike the use of the term CYLINDER rather than TRACK Let s clear the air A cylinder is all tracks of the same number on all surfaces of a drive If the drive is a single sided floppy there is ONE track per cylinder and the terms are interchangeable But LDOS supports much more then single sided floppies When we say cylinder on a SA 506 hard drive we are referring to the imaginary cylinder that is created by the same track on each of that drive s FOUR surfaces So this drive has four track number X s but only one cylinder X It s true Tim Mann did get his hair cut Dick Konop also shaved off his beard Guess we are all joining the Establishment This section of the newsletter stems from users asking LDOS Support Why does LDOS create a parity error Well LDOS
43. ntional Model I field statement while Example 1B will represent a field statement using LBASIC s Blocked Files Note that for every 10 logical records six bytes are wasted in conventional Model I Basic as logical records cannot span sector boundaries Example 1A FOR L 1 TO 10 FIELD 1 L 1 25 AS DMS 5 AS AR 1 L 4 AS AR 2 L 8 AS AR 3 L 8 AS ARS 4 L NEXT L Example 1B FIELD 1 5 AS AR 1 4 AS AR 2 8 AS AR 3 8 AS ARS 4 Let us now assume that we wish to perform a GET of a logical record and utilize some field of that particular record The variable LR contains the record number we wish to GET and the variable NF contains the number of the field that we wish to access The following examples will show how the logical record in question will be accessed Example 2A demonstrates how access is performed using conventional Basic while Example 2B demonstrates how access is performed using LBASIC Blocked Files Example 2A PR INT LR 1 10 1 SR LR PR 1 10 GET 1 PR XXS ARS NF SR Example 2B GET 1 LR XX AR NF Page 11 Hopefully the above paragraphs and examples will clear up any remaining questions that exist concerning LBASIC and its use Linking to the LDOS Command Interpreter from a Machine Language Program by Roy Soltoff One of the more specialized operating system functions available to the assembly language programmer using LDOS is access to the com
44. on and had no real bearing on the clarity of descriptions or examples This list will be arranged by section and page number starting from the front of the manual Page 16 SYSTEM DEVICES PAGE 4 The CL device section refers to a KSR CMD utility program This program was a stripped down version of LCOMM and was not included on the release disk It was felt that since LCOMM contains all the functions of KSR nothing would be gained by placing KSR CMD on the disk LIBRARY COMMAND lt COPY gt Using the LRL parameter will always cause the destination file to have the specified LRL regardless of the destination file s LRL before the copy LIBRARY COMMAND lt DO gt No commands that require removing the system disk from drive 0 may be included in a file for DO processing LIBRARY COMMAND lt LOAD gt PAGE 1 The addresses for the LOAD command should be changed from X 5200 and X 5300 to X 51FF and X 52FF respectively LIBRARY COMMAND lt SYSTEM gt PAGE 7 In the SYSGEN parameter section item 3 states that any routines loaded into memory and protected with HIGHS will be saved in the configuration file It should also say that ALL memory from the physical top down to HIGHS will be saved in the configuration file LIBRARY COMMAND lt VERIFY gt All disk writes are automatically verified during any type of BACKUP LIBRARY COMMAND lt XFER gt The source and destination disks used for the XFER command must have di
45. ove example if lt ENTER gt is pressed after the backspacing has been performed and before the lt gt command is given you WILL be placed in the edit mode 6 If you intend on using CMD X or CMD N the files BASIC OVX and BASIC OVN must be present on some disk in the system BASIC OVX is the overlay which contains the cross reference utility BASIC OVN is the overlay which contains the renumber utility Page 9 Also if you wish to use either of these utilities you must NOT have renamed LBASIC to BASIC Doing so will cause the error PROGRAM NOT FOUND to appear after the operation has been completed In addition you will leave LBASIC and control will be returned to the operating system 7 The proper syntax for the CMD X command is as follows CMD X devspec filespec parameter lt title gt Note that there is no comma required between the devspec filespec and the parameter as was shown in the first edition of the manual 8 NEVER use CMD X or N if your program contains a line 0 Doing so will cause unpredictable results and your program may be erased from memory 9 When using CMD X variables in a PRINT statement that are packed together may not appear in the variable listing For example suppose the following line appears in a program 100 PRINT ASBSCSDSESFS Because the variables are packed together i e not separated by semi colons or spaces some may not appear in the cross reference listing To assur
46. s not a HOBBY or PART TIME product for us There is a full time staff of 5 programmers and 2 support persons to provide and maintain this product This is in contrast to other companies providing operating systems for the TRS 80 MOO I amp III even Tandy doesn t have as many system programmers working for you As charges and services change from time to time please bear with us as we will always try to give you the best possible product or service at a fair not losing price The 800 line service will remain but the hours of service will be modified temporarily The new hours will be 10 12am and 4 6pm Central time Monday through Friday This is to minimize the interruptions in our programming department Should these time slots become inadequate they will be expanded as needed You will be notified in this newsletter and on the MicroNET LDOS board of any changes in these hours If the label on your MASTER disk does not show 2 in the Update row send in your MASTER disk along with 5 00 as soon as possible for your 5 0 2 update Even if you don t need or want the new features there have been several small bugs repaired in this version which may keep you from having a problem As usual send your disk packaged carefully as the replacement of a damaged master disk will cost you an additional 5 00 Address your disk to LDOS Support at the same address given above for LSI Make checks payable to Logical Systems Inc LDOS owners in Eng
47. ualified most of my statements with the words if you have a Radio Shack interface Well what if you have a Lobo LX 80 In that case things are not quite so nice but it IS possible to use an LX 80 with a clock speedup There seem to be two components of the LX 80 which do not function at the fast clock speed the boot ROM and the SIO chip The SIO chip is better known to LX 80 owners as the RS232 option It is what drives the two serial ports in the LX 80 if you have them The 10 chips supplied by Lobo are only rated at 2 5 MHz and generally do not work at 3 54 MHz The only cure I know of for this problem is to buy a 4 MHz SIO chip These are available but expensive I get around the problem by doing a SYSTEM SLOW every time I enter LCOMM which is the only time I use my serial ports The LX 80 boot ROM presents a more serious problem It is used during booting and also contains all the code for the LDOS LX 80 disk driver routines If you attempt to access this ROM when operating at the fast clock speed you will read back invalid data and typically cause a rather dramatic crash Once again SYSTEM FAST becomes SYSTEM CRASH Fortunately there is a way around this too Of course you could run a wire into the LX 80 to slow down the clock during disk I O but this negates much of the benefit of having a clock speedup since this type of mod actually slows down the clock whenever the drive motors are running even if there is not act
48. ually any I O going on Page 15 First of all you must make the hardware change I described above to allow rebooting after the speedup has been turned on The software patch will have no effect on the LX 80 Secondly you need to use a program I have written called FAST CMD included in the program section of this newsletter This program acts as a front end to the disk drivers slowing down the clock before entry to the ROM routines and speeding it up upon exit if SYSTEM FAST was active When you execute this program it relocates itself to high memory protects itself and patches itself in between the system and the ROM disk drivers It then automatically executes a SYSTEM FAST After this you can freely execute SYSTEM SLOW or SYSTEM FAST commands to turn your speedup on or off as needed Under LDOS 5 0 2 you will be able to do a SYSGEN to save FAST CMD after you have called it in Under earlier versions of LDOS you must execute it as a direct command or AUTO command only it will not SYSGEN properly Well that about wraps it up If you follow the above procedures you should be able to run quite well with a speedup mod Mine is so convenient that I am hardly conscious I have it but I really notice it when I am running on a computer without one it s S L O O O O W If you have any further comments or questions about speedup mods feel free to write LDOS Support Please do not call on the 800 line to discuss this subject
49. uctions First of all when the motor ona 5 floppy disk drive is started it is necessary to wait until it comes up to speed before you attempt any I O This waiting time is typically 1 2 second to 1 second depending on the specifications set down by the drive manufacturer Secondly some operating systems use a delay loop to allow a certain amount of time for an index hole to go by before they decide that Page 13 there is no diskette in a drive But most importantly after any command is passed to the TRS 80 s disk controller chip FDC there is a certain settling time reguired before the status bits that are returned to the CPU are valid This can be as long as 100ms according to the Western Digital 1791 data sheet The need to allow for this settling time accounts for the PUSH HL POP HL or EX SP HL instructions found in several places in TRSDOS and other operating systems How does LDOS deal with the need to increase its timing loops when running with a fast clock mod This is done by means of the SYSTEM FAST and SYSTEM SLOW commands When you execute a SYSTEM FAST LDOS sets a system flag bit informing the disk drivers that the CPU clock has been speeded up It also outputs a 1 to port X FE which seems to have become the standard method for switching clock speedup mods on The speedup mod is left on until you execute a SYSTEM SLOW at which time LDOS resets the flag bit and outputs a 0 to port X FE While the fast clock flag
50. xt should read Close a file or device X 4442 and X 4445 the text should refer to LOGICAL rather than PHYSICAL records GETDCT is located at X 478F not X 468F as stated The text should read Get Drive Code Table address TECH INFO lt RAM STORAGE ASSIGNMENTS gt PAGE 6 JFBC should be named JFCBS JFCB should be named CFCBS These corrections should take care of all the missing and incorrect data in the manual If you have found other errors please send us a letter detailing the section page and what the error is don t use the 800 number This section of the newsletter contains some Filter programs and other files contributed by LDOS owners Most of these files are also in the data base of the LDOS MicroNET bulletin board Please remember that these are not official LDOS programs any questions comments etc should be addressed to the person that contributed the program not to LDOS Support In this issue most of the programs have been contributed by LDOS Support people especially Tim Mann This section of the newsletter is specifically meant for interchange between LDOS users We are always looking for contributions for this section Note that the hex program listings must be put into the proper load module format before they can be used There is a program included in this section called BINHEX BAS which will do the conversion for you To use the program follow these steps 1 Use Scripsit Electric Pencil
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