test-drb May 2019

test-drb@ccmp.vtda.org

149 participants
165 discussions

by pbirkel＠gmail.com

Aficionados; I'm interested in acquiring an HP1000 A900, in any form-factor. (http://www.hpmuseum.net/display_item.php?hw=594) Basic need would be a chassis/backplane/PS and minimal set of CPU/memory/HPIB-controller/terminal-IO PCA, however I'd be interested in simply acquiring a PCA-set and I'll work the chassis/backplane/PS separately. Even single PCAs would give me a helpful push forwards. And I need to stick to my hobby (beer") budget. I'm located in Maryland, USA, and pretty sure that the cost of overseas shipping would be ghastly for a chassis. But maybe not as bad for the tower configuration as for the rack-mount. If I understand correctly, the CPU consists of: 12201A A900 Sequencer Card 12202A A900 Data Path Card 12203A A900 Cache Controller 12204A A900 Memory Controller 12220A 768KB RAM (Or I presume 12103D 1MB, 12221A 3 MB, or 12221B 8 MB.) I imagine that I'll need to synthesize my own OTT "frontplane" for the memory. 12009A HP-IB Controller 12040D Asynchronous Multiplexer interface board Thank you for your insights, and opportunities (I hope), paul (offlist at pbirkel at gmail.com)

5 years, 8 months

DEC disc pack inspection unit on eBay

by bobalan＠sbcglobal.net

There's a mis-categorized? disk pack inspection unit up on eBay. Might be of use to someone. https://www.ebay.com/itm/Early-Digital-Equiment-Corp-DEC-Portable-Briefcase… Bob -- Vintage computers and electronics www.dvq.com www.tekmuseum.com www.decmuseum.org

5 years, 8 months

Possible PUTR bug?

by charlesmorris800＠centurytel.net

John Wilson confirmed that his program was designed to work with one floppy and an HDD. He says strange things happen if one tries to use two floppy drives instead... just as I found ;) I removed the second floppy drive, dug out an old 540 MB hard drive (with Win 95 on it) and hooked it up to the PC. Started Win95, then "Restart the computer in MS-DOS mode", copied PUTR to the C: drive and started it. PUTR now works perfectly, transferring files in both directions to an the emulated RX33 (3.5" floppy). The PDP-11 can read and write those disks on its generic 3.5" floppy "RX33", too. :) Now I just have to figure out the PC partitions/hard drives to make using PUTR as simple as possible.

5 years, 8 months

Bug in PUTR?

by charlesmorris800＠centurytel.net

I'm having trouble copying files from my PDP-11 (RT-11 format) into an old Windows box using the last version of PUTR. It appears that WinXP does strange things with the hardware (3.5" 1.44 MB drives aren't actually RX33's although my RQDX3 controller believes they are). So I made an MS-DOS boot disk and run PUTR directly on MS-DOS (instead of the WinXP DOS window). Unfortunately MS-DOS 6.22 can't recognize my hard drive since it's NTFS-formatted, so it all has to be done in floppies. Both WinXP and MS-DOS know that A: and B: are two separate drives. Likewise the BIOS settings. I can copy files in DOS and Windows back and forth between the two drives. And I can MOUNT B: as a logical device DU0: (or without a logical device name, as B: /RX33 /RT11), and read its directory. But when I try to copy a file from A: to DU0:, the B: drive light flashes briefly, and then PUTR tries to write over the A: drive (blocked by the write- protect tab once I wised up)! So how on earth can the BIOS, MS-DOS and WinXP all know that A: and B: are two separate drives, but PUTR tries to write to A: even though the command is to write B: ?? I also tried switching the PUTR disk into B: and the RT-11 formatted disk to drive A:. Same problem (tries to write over the source disk which is now B: even though the output filespec is clearly A). I had a look at the code but nothing's leaping out at me. Although it's been many years since I wrote any 8086 code...

5 years, 8 months

Looking for DEC M7264-CB Troubleshooting Documentation

by vintagecomputersmn＠gmail.com

Hello, As part of my H11A project, I am trying to debug my M7264-CB LSI-11 CPU module. When powered on, the CPU does not respond to the Run/Halt switch either on the front panel or via the console. I found engineering schematics for the M7264 online, but I was wondering if any in depth troubleshooting material existed online (Logic probe points, debugging steps, etc...). Thank You, Gavin

5 years, 8 months

IBM 1052 keyboardless printer on eBay

by steven＠malikoff.com

Sadly, way out of my price range. I'd dearly love it though: https://www.ebay.com/itm/IBM-1052-Selectric-Keyboardless-Golf-Ball-Console-… Seems to be missing the 1052 / 2741 platen knobs unique to the printer-keyboards and I/O Selectrics BUT if anyone is interested I have almost finished the CAD model for this (measured from the 2741 platen I still have). They just need to be 3D printed off and the aluminium bosses machined and tapped: http://www.surfacezero.com/g503/data/500/IBM_1052_and_2741_platen_knob.jpg Steve.

5 years, 8 months

Looking for DEC M7264-CB Troubleshooting Documentation

by jnc＠mercury.lcs.mit.edu

> From: Mister PDP > the 'Run' light does not come on when the switch is toggled Yeah, it wouldn't come on full unless it somehow fell into a loop of some kind - very unlikely. (Does that model LSI-11 have the on-board memory? I'm too lazy to look it up! :-) And what do you have the CPU jumpered to do on power-up? (ODT, 173000, etc.) But I would expect to see a brief flash. (Note: I don't have an LSI-11 plugged in to check this, I'm going by memory - the -11/23 certainly does the brief flash; if need be, I can pull out an -11/2 and plug it in, once I figure out if they are safe in Q22 backplanes.) I'd check the power voltages, and the clocks on the CPU board, and then look at BSYNC, etc to see if there's any hint that the ODT ucode is trying to read the console registers. No activity on BSYNC -> the ucode's not running. 'Small' QBUS systems - i.e. a single backplane - are OK to run with no termination on the far end of the bus (the CPU board includes pullups for that end), that shouldn't be an issue. Noel

5 years, 8 months

Looking for DEC M7264-CB Troubleshooting Documentation

by jnc＠mercury.lcs.mit.edu

> From: Mister PDP > I was wondering if any in depth troubleshooting material existed online I am not aware of any; I would be glad to be corrected. Unlike the early gneration of UNIBUS CPU's, these generally weren't intended for internal fault analysis and repair - module swapping and replacement was the intended approach. The LSI-11 manual (EK-LSI11-TM-003) has a tiny bit of detail on how the CPU board works (pp. 4-3 - 4-13), it's probably worth reading that before diving into the CPU board internals. Things I'd check to start with - all the power voltages, and then the clocks. If those are all OK... BTW, for any serious fault analysis on these things, you'll need a 'scope/logic analyzer. > When powered on, the CPU does not respond to the Run/Halt switch either > on the front panel or via the console. When you say 'does not respond', what's the symptom? Is the console ODT not running (which could have any number of causes)? The whole system has to be more or less running for ODT to work. I'd start elsewhere - e.g. does your mounting box have the 'run' light? (It's driven by an output of the CPU card.) Does that display any activity? Time to look at e.g. BSYNC, etc to see if the CPU is trying to read/write the console registers. Noel

5 years, 8 months

PDP-11/40 available, Arizona

by derschjo＠gmail.com

I have no affiliation with the person who owns these items, I'm merely relaying information. These machines were offered to the LCM+L but we've met our 11/40 quota :). We figured someone here might be able to provide a good home, and the seller asked us to pass the offer along. Contact information is below: Email: kristina.kaur at mac.com List of items offered: DEC PDP 11/40 from approx 1973 Other associated equipment may include punch card machine (key punch), tape drive(s), free standing dot matrix printer, terminals (approx. 12). Condition of items: Very good condition. Running or close to running. Most peripherals have been offline and stored. How have these items been used and/or stored?: Running in filtered air. Desert, dry climate. Extent or weight of these items: The DEC PDP is 6-8 cabinets.

5 years, 8 months

Wanted: SCP-301, Seattle Computer Products 8086 Support Board

by ethan＠757.org

Looking for a SCP-301 S100 board, SCP 8086 Support Board. Have the CPU board. Any leads appreciated! -- : Ethan O'Toole

5 years, 8 months

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test-drb May 2019