test-drb August 2019

test-drb@ccmp.vtda.org

161 participants
150 discussions

Convergent Technologies NGEN and Datapoint monitor

by ce.murillosanchez＠gmail.com

Good evening, folks... Does anybody know if Datapoint made monitors for Convergent Technologies? In my "near junk" section I have some modules that someone stored in a warehouse next to a carpenter shop and under bombardment >from bats and birds.? The modules were made by Convergent Technologies and I never did much about them because of their extremely dirty state and also because of the lack of a keyboard.? I have: - Two CP-001/8 cpu modules (80186 at 8MHz, 256KB RAM, 6845 video IC) - Four 5 1/4" dual-floppy modules (each has two Mitsubishi M4853 half-height drives) - One GC-001 graphics controller - Two PS-001 power supplies, one is missing parts and then, a monitor that by the looks and controls is a VC-002 15" to be used with the GC-001, except that it is labeled as: Datapoint Corp. Model 97-1224-001 Serial 934055 Other marks:? 53-00355-00???? 5-84 So, do you guys know if Datapoint made monitors for others? Carlos.

5 years, 6 months

XXDP on PDP-11/03

by jnc＠mercury.lcs.mit.edu

> From: Paul Koning > Isn't the interrupt disabled by RESET? Nope. On the -11/03 and KDF11-A, BEVNT is wired straight into the CPU, and there's no internal register to control it. The BDV11 does have a register which can enable/disable the LTC (it connects BEVNT to ground via a transistor when the appropriate register bit is cleared); but, ironically (given your question), BINIT/RESET does _not_ clear that register! Only BPOK does. (My theory is they were short of a bus receiver for BINIT, and rather than put a whole extra chip on the card...) So, once on, it has to be explicitly turned off, or the 'boot' switch (which toggles BPOK) has to be hit. The KDF11-B and all KDJ11 machines do have the LTC register, which operates 'correctly'. Noel

5 years, 6 months

XXDP on PDP-11/03

by jnc＠mercury.lcs.mit.edu

> From: Jerry Weiss > I turned BEVENT off and it boots successfully. I am not immediately > sure why this is necessary. If an LTC interrupt happens before the OS has set up the LTC vector, etc, hilarity ensues. E.g. the LTC has to be turned off before UNIX V6 will boot on an -11/23: http://gunkies.org/wiki/Running_UNIX_V6_on_an_-11/23 I discovered this the hard way; I roached the disk on my simulated /23 when I didn't. Noel

5 years, 6 months

ADM-3A question

by charlesmorris800＠centurytel.net

After hanging vertically for 36 hrs in a hot upstairs room, more goop seeped out from under the keyboard. It now works again. Whew. While running on the bench for burn-in testing, a cursor problem suddenly appeared... it would only move every other keystroke. With the technical description and schematic at hand, it wasn't hard to track down a 74LS193 up/down counter with a blown (floating) LSB output. Confirmed by manually toggling that bit and the cursor would move back and forth one position. Meanwhile I removed the bad chip and put in a DIP socket. Naturally my TTL collection didn't have an 'LS193 so I'm waiting on that. So I have a 24 line, 1 column terminal :) The monitor was occasionally intermittent (no display at all, no HV, +15 and drive signals OK). It seemed to change with movement of the wiring harness >from the main board to the monitor, too. I reseated the edge connector on its PCB and it seemed to be fixed - but then the VERTICAL deflection collapsed and tweaking the height adjustment caused increasing loss. The 100 ohm pot to the base of the vertical output transistor had picked that moment to go open. Changed that out and readjusted everything - so far so good after another hour of run time. This ADM-3A could have been unpowered (and in a storage area without climate control) for a very long time. I wonder if that contributed to the failures I'm seeing... hope there aren't any more until I get to use it for a while on my PDP-8/A (or 11/23+). --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus

5 years, 6 months

XXDP on PDP-11/03

by dj.taylor4＠comcast.net

Recently, I assembled one of the RX02 emulator boards developed by AK6DN.? I am using it presently in a BA11-M box with PDP-11/2 cpu (really basic 16 bit system).? I put the disk images from github on the SD card (RT11 V5.07 and XXDP not sure what version). The box has a BDV11 bootstrap / terminator board and I use this to boot the RX02 emulator.? Works fine when I boot RT11, however I can't boot XXDP - it halts at 000104. Do I need to use a different version of XXDP to run on the PDP-11/03? Doug

5 years, 6 months

Compaq SystemPro XL Service Manual or PSU Schematics

by cctalk＠ibm51xx.net

Hello All, Does anyone out there by any chance have the Service Manual for a Compaq SystemPro XL or at least schematics to the PSU? Trying to revive one of these systems and the PSU is not working. TIA! -Ali

5 years, 6 months

Electr* Engineering

by athornton＠gmail.com

At Rice in the early 90s the department was "Electrical and Computer Engineering" if my hazy memory serves. The genealogy of Computer Science departments (and their curricula) (at least in the US) is also weird and historically-contingent. Basically it seems to have been a tossup at any given school whether it came out of the Electr[ical|onic] Engineering department, in which case it was memories and logic gates and a bottom-up, hardware-focused curriculum, or out of the Mathematics department, in which case it was algorithms and complexity analysis and a software-focused curriculum. Adam

5 years, 6 months

IBM 026/029/129 ribbons

by cctalk＠ibmjunkman.com

Just for reference the following site has ribbons for the subject card punches. https://www.aroundtheoffice.com/IBM-026-Keypunch-Ribbon/productinfo/RP-520-I BM/ I bought some a few years ago. As I understand it he makes a batch every year or so. I don't know but he might like the used reels back to use again. :-) Donald

5 years, 6 months

Anyone have a mid-80s Robinson-Nugent connector catalog?

by aek＠bitsavers.org

Or some RN 68 pin CLCC sockets, or even a part number for them? I tried buying a 1981 RFN catalog, but they weren't in there. I have a bunch of IMS 80186 slave cards with the CPUs pulled Of course, they didn't keep the caps. RN was bought by 3M and I've been unable to even find a part number for these sockets. I'm hoping not to have to replace the sockets to get these boards working. Pics of what I need are here https://twitter.com/bitsavers/status/1161075014235385857

5 years, 6 months

Pertec Interface Cable Length

by dj.taylor4＠comcast.net

I have a question about cable length - any electrical engineers in the house? Connected a Qualstar 1260 tape drive to an Emulex TC02 qbus tape controller in a pdp-11/53.? The interface is pertec with 2 50 pin cables. When I use a pair of short flat ribbon cables, 18 and 30 inches each, it works.? Under RT11 I can INIT, Copy, DUMP, do a Directory. It doesn't work when I use a pair of 5 foot long flat ribbon cables.? Are they too long?? Do I need twisted pair type of cable?? Is it possibly a termination problem? Doug

5 years, 6 months

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test-drb August 2019