test-drb

test-drb@ccmp.vtda.org

101090 discussions

by van.snyder＠sbcglobal.net

In about 1974, for my senior undergraduate project, I wrote microcode to convince a Varian V70 that it was actually an IBM 1130. Being substantially more modern hardware, it was much faster than a real 1130. If anybody wants microcode and flow diagrams, and listings for the I/O simulation (which ran in 620/f mode), I'm happy to send them. Van Snyder van.snyder at sbcglobal.net

5 years, 3 months

Books I no longer need

by van.snyder＠sbcglobal.net

So far, two people have asked for "Programming HP 21MX Computers." So that I don't have to decide who gets it, I've put it on EBay for a 7-day auction with a starting bid of $0.99. https://www.ebay.com/itm/224184669206 It has a cheap "perfect" binding, and it's 3-hold punched, so it could be disassembled and scanned, but I don't want to be the one who does this. Van Snyder van.snyder at sbcglobal.net

5 years, 3 months

Finnish museum needs financial help

by sales＠elecplus.com

https://pt.gofundme.com/f/exhibition-of-agora-computing They really need donations so they can get going again. Can anyone help? -- Cindy Croxton Electronics Plus 1613 Water Street Kerrville, TX 78028 830-370-3239 direct

5 years, 3 months

Microsoft C 6.0 manuals

by tomas＠basun.net

Hi again, Am also looking for the manuals for Microsoft C 6.0, preferably in a digital format. /Tomas

5 years, 3 months

Handheld systems archive CD-ROM

by tomas＠basun.net

Hi all, Am wondering if anybody knows how to find a copy of the "Handheld Systems Archives CD-ROM" that was sold through the domain cdpubs.com 20-30 ywars ago. /Tomas

5 years, 3 months

Tips on reviving a TU56 + TD8E?

by mosst＠SDF.ORG

Hi All, I've recently bought a TU56 for my PDP-8/e, and am looking for some advice on getting it to work. Over the course of a few weeks I fixed odds and ends with the drive (motor run capacitors, damaged wires, transistors, etc.), and for a few days the right drive worked very reliably. I could read existing tapes, write to them, and format fresh tapes. (A write-up to this point is here: www.vcfed.org/forum/showthread.php?76935) (A good source for new motor run capacitors: https://www.ebay.com/itm/142631210678) However, this changed when I wrote a file to an existing tape, only to find that the directory structure had somehow been corrupted in the process. Out of curiosity I mounted a scratch tape that I knew I could format before and tried to format it again, the result was a BLOCK NUMBER ERROR PHASE 4. When running the TD8E MAINDEC it's apparent why - when set to display the block number in the accumulator for the tape I tried to format, every third bit appears to stick or glitch out. The tape I think I corrupted however appears to count up and down the blocks correctly. (Video here: https://streamable.com/bh8f7p) I tried swapping the G888s around to see if it made any difference, but nothing changed. I then turned my attention to the cabling and the TD8E. Somewhere along the line things got worse, and now running TDFRMT just results in a "SETUP?" error when trying to format a tape. I've tried running the TD8E MAINDEC (DHTDAB), and managed to get it to pass the following tests: -Operator Intervention -Data Register -Command Register -Initialize -SDLC, SDLD, SDRC, and SDRC and AC Clear -Single Line Skip Instruction and Logic Test -Quad Line Skip Instruction and Logic Test However, once it reaches the Timing Error Skip Instruction and Logic Test, it fails with the following: >TIMING ERROR SKIP INSTRUCTION AND LOGIC >TIMING ERROR STATUS BIT NOT SET IN COMMAND REGISTER > >TIMING ERROR DOES NOT CLEAR WRITE FLIP/FLOP I also found some tests that check the Data and Command Registers by accepting input from the switches and displaying the result in the MQ. These work fine, although though doing so I discovered that I had stuck bits on the MQ on one of my Major Registers boards. I swapped with a spare for now and will look at that later. Lastly I found a copy of the source for TDFRMT so I could see what exactly was causing the "SETUP?" error. I noticed there's several things that can cause that error (the JMPs to ERCHK), so I replaced the first JMP ERCHK with a halt and sure enough it did halt there. /SEE IF THE DRIVE IS OK 003224 6774 RSTSM, SDLC /LOAD CR TO CLEAR TIMEING ERROR 003225 6775 SDLD /LOAD DATA BUFFER TO CLEAR S Q FLAGS 003226 1162 TAD DT0400 /SET WRITE 003227 1027 TAD DTA /GET UNIT 003230 3257 DCA SAV /STORE IT AWAY 003231 1257 TAD SAV 003232 6771 SDSS 003233 5232 JMP .-1 003234 6774 SDLC 003235 1257 TAD SAV 003236 6774 SDLC /LOAD THE TRANSPORT 003237 6776 SDRC /READ THE COMMAND REGISTER AND CHECK IT 003240 7006 RTL 003241 7004 RAL 003242 7500 SMA /CHECK WRITE TO BE SET 003243 5260 JMP ERCHK /WRITE IS NOT SET <<<---Halts here if changed to HLT. 003244 7004 RAL /CHECK WLO 003245 7510 SPA 003246 5260 JMP ERCHK /WLO 003247 7004 RAL /CHECK SELECT AND TIMING ERROR 003250 7710 SPA CLA 003251 5260 JMP ERCHK /SELECT OR TIMING ERROR 003252 4777' JMS NUDTA /CHECK OTHER DRIVE IF ANY 003253 5213 JMP RSTSM-11 /CHECK OTHER DRIVE 003254 5655 JMP I .+1 003255 1400 STMK 003256 0000 CNTERL, 0 003257 0000 SAV, 0 Does anyone have any hints on what I should check from here? Regards, -Tom mosst at sdf.org SDF Public Access UNIX System - https://sdf.org

5 years, 3 months

8 inch floppy head pad adjustment

by cz＠alembic.crystel.com

Working on cleaning up my RX02 drives: I've taken the 8 inch floppy units out of the case/chassis and have been cleaning dust and such off the whole assemblies. One thing I noticed: There is a pad opposite the head that comes down when a solenoid is energized to provide pressure against the read head. Makes sense, it also has a pad that presses against the floppy disc itself, probably to keep it from jittering. However I noticed on both heads that the bracket is adjusted all the way down. This means that even when the solenoid is not energized the head pad is pressing against the disk and pushing the disk against the head. Is this normal? I would think this would result in the floppy always being pressed against the head and quickly wearing out the disk. The whole point is to let the disk float against the head, only letting the pad push things into contact when doing a read. Do I have this right, and is adjusting that that assembly proper when the pad puck is not touching the disk when up, but is touching it when down? C

5 years, 3 months

Books I no longer need

by van.snyder＠sbcglobal.net

I have some books I no longer need. Is this a good place to offer them? WordPerfect Wiorkbook for IBM Personal Computers Microsoft MS-DOS 5.0 User's Guide and Reference Microsoft MS-DOS 5.0 Getting Started WordPerfect Version 6.0 DOS Reference (along with a CD) WordPerfect Add-Ons Catalog WordPerfect Software Product Catalog WordPerfect Version 6.0 DOS Getting Started for the New User WordPerfect Shell Version 4.0 DOS User's Guide WordPerfect Version 6.0 DOS Learning WordPerfect WordPerfect for UNIX 7 Installation and Administration Guide WordPerfect for UNIX 7 User Guide WordPerfect for UNIX 7 Clipart Guide Van Snyder van.snyder at sbcglobal.net

5 years, 3 months

Apple Lisa Software List

by seanellis9＠gmail.com

Hey all, the past couple of weeks I've been working on compiling a list of all known Lisa software, and trying to determine if it was for the 1 or 2, if it ran on Office System, XENIX, UniPlus, etc. and the dumped status of each title. If anyone's got any tips or pointers, let me know and I'll get the list updated. https://docs.google.com/spreadsheets/d/1STG0Le_8dMHRLf026x6YfXzRQm2hD0igeZV…

5 years, 3 months

Vintage 1976 Digital Computer Controls, Inc. D-116 Computer Maintenance Manual

by microtechdart＠gmail.com

Just wondering if anyone here might have been the winning bidder on this one... https://entrex480.blogspot.com/2020/10/vintage-1976-digital-computer-contro… https://www.ebay.com/itm/284026555447 -- Best always, AJ Palmgren http://Entrex480.com

5 years, 3 months

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