test-drb

test-drb@ccmp.vtda.org

101090 discussions

Could somebody please help me identify this board?

by mike.niswonger＠cox.net

The "CG" logo on the corner appears to be one of the many Compugraphic logos. Possibly a a board from a custom phototypesetter that drove a CRT to expose the photomask (film)? On 12/06/2016 06:57 PM, Chris Pye wrote: > I?m moving my collection and found this board amongst some others. > > https://drive.google.com/open?id=0B0m4VYF4tIU5aXJMSHBwUDJMUWM <https://drive.google.com/open?id=0B0m4VYF4tIU5aXJMSHBwUDJMUWM> > > Cheers, > Chris

8 years, 4 months

M7869 KY11-LB ROM dumps

by tomjmoss＠googlemail.com

Hi All, I've been testing an M7869 recently and noticed that my 11/34 would give a BUS ERR whenever it was halted or if I tried to read from the switch register, so I used the "wholly scientific" fingerpoken troubleshooting method and noticed the ROM at U33 (P/N 23345A9) was piping hot. Does anyone have a dump of this ROM that I could use? Regards, -Tom

8 years, 4 months

Wanted: Terminator for an RL02

by tomjmoss＠googlemail.com

Hi All, Does anyone have a spare RL02 terminator for sale? Regards, -Tom

8 years, 4 months

Have lunch with Lee Felsenstein

by cctalk＠snarc.net

Only 12 hours left to bid on lunch with legendary computer engineer Lee Felsenstein! This benefits Vintage Computer Federation, a 501(c)3 non-profit devoted to enabling collectors, growing the hobby, and spreading awareness of computer history. Please see https://www.charitybuzz.com/catalog_items/lunch-for-3-with-personal-computi….

8 years, 4 months

Could somebody please help me identify this board?

by pye＠mactec.com.au

I?m moving my collection and found this board amongst some others. https://drive.google.com/open?id=0B0m4VYF4tIU5aXJMSHBwUDJMUWM <https://drive.google.com/open?id=0B0m4VYF4tIU5aXJMSHBwUDJMUWM> Cheers, Chris

8 years, 4 months

Miniscribe 6053 HD PCB needed

by mhs.stein＠gmail.com

Hi all, I accidentally dropped something on a Miniscribe 6053 44MB HD and cracked the board; looks pretty dense and tricky to repair so I'm hoping that there's a kind soul out there somewhere who happens to have a 6053 doorstop and can spare the circuit board for a good cause? Removing the board shouldn't impair the door-stopping capability in any way... Mike (in Toronto)

8 years, 4 months

Double Buffer RK11-C

by jnc＠mercury.lcs.mit.edu

> From: Glen Slick > You should also hang out at vcfed forum in addition to hanging out here. I barely have time to keep up with the things I'm already into (actually, strike that - I _don't_ have time to keep up already :-)! So I'm going to have to pass. Interesting about the FP11 stuff, though. I wonder, however, if those 11/20 mentions are more aspirational, rather than something that was actually done, and later dropped? I say this knowing a modest amount about how the KA11 CPU in the 11/20 works, and a bit about how the FP11-B interfaces to the host CPU. For one thing, it would take some modifications to the KA11 to recognize floating point instructions, so that it can wake up the FP11-B to handle them. But that turns out to be the easy part; it would take further mods to the KA11 because the FP11-B expects the host CPU to do data fetches, etc on its behalf. (See Figure 2-3 in the FP11-B MainManual.) This latter function can't be off-loaded onto a separate interface unit, as it needs access to register contents held in the CPU. I don't have the time to look into this further, but if someone is interested they'd need to study the FP11<->CPU interface, and in particular look at how the KB11 supports memory operations requested by the FP11-B - I wouldn't be suprised if there's some microcode in the KB11 to support those memory operations. Noel

8 years, 4 months

Intel C1101A

by vintagecomputer＠bettercomputing.net

Putting this out there for those hopefully in the know. I have been acquiring date-correct ICs and parts for my Mark-8 project, which is years down the line. I'm planning to build it on very carefully replicated clone boards, based off my originals. For my purposes, I'm trying to keep ICs early 1975 or earlier. Most Mark-8s that I've seen have P1101a plastic encapsulated RAMs. Most are Intel brand, but I've seen some that I think might be National or something.. they just say P1101A on top. The only source other than ebay that I have are those big chip vendors like Summit. And the problem with them is they aren't always precise about date codes. The P1101A, because they were produced for years, have a wide range of codes and the places I prospected them from couldn't guarantee 75 or prior. To my surprise, I found a few places had C1101A. They are white ceramic, gold legs. They have a 'batch code' of F1268. I got 16 of them for $14 each. I was going to get 32, but Summit also surprised me with 5 1973 vintage Signetics n8263s @ $25 each. I hadn't been able to find any pre-1980 so I snatched those.. but that put me beyond a budget where I could buy 32. I figured I'd buy 16 chips for now and then buy another 16 the next month. Now of course, the chip houses have turned tables on me. They want $48 per chip instead of $14 like last time. And checking around, that seems to be uniform. Now, I'm not averse to paying that, though it will sting. But I want to make sure my assumptions are correct.. that these white vintage ICs are in fact pre-76. Can anyone confirm that? The info out there is a little vague. And would it be totally out of place for C1101as to be on a Mark-8? Could a hobbyist have had a source for them, beyond having some lying around?

8 years, 4 months

UNIBUS/QBUS interface chips Was: Re: MEM11 update

by jnc＠mercury.lcs.mit.edu

> From: Pete Lancashire > Do you or someone have a list of all the Unibus bus chips ? I have seen the following bus interface chips used on DEC UNIBUS boards: Drivers: 8881 - Sprague, Signetics - Quad NAND Receivers: 380 - Signetics - Quad NOR 314 - Signetics - 7-input NOR 8815 - Signetics - 4-input NOR 8837 - National Semi - Hex receiver (aka Signetics N8T37) 8640 - National Semi - Quad NOR Transceivers: 8641 - National Semi - Quad transceiver The actal complete part number can vary depending on the manufacturer; e.g. the 8641's are usually DS8641N, from NatSemi, and the 380's are usually SP380A's or SP380N's. Where the basic number is not included (as with the 8T37 for the 8837) I have given it. The following chips have been used by DEC to interface to the QBUS, and I have seen many of the above chips (e.g. 8641's) used there too, so I think chips seen on one bus could be used on the other: Drivers: 7439 - Various - Quad NAND Transceivers: 2908 - AMD - Quad latching transceiver with tri-state output I _believe_ the following chips are also usable as UNIBUS/QBUS interface chips, but I'm not sure if I've seen one used there: Transceivers: 8836 - National Semi - Quad NOR 8838 - National Semi - Quad transceiver (aka Signetics N8T38) Quite a zoo! Noel

8 years, 4 months

Intel C1101A

by jnc＠mercury.lcs.mit.edu

> From: Mark Moulding > I did a bulk buy of some 1960's era miniature vacuum tubes (500 pcs) > for around 50 cents each; the next time I looked, the price from all > vendors who had them had jumped to around $3 There is another possibility (one which I think I saw happening when Guy and I were buying DS8641's, which we previously discussed here), which is that if multiple vendors have stock, an initial order might buy up the ones with the cheapest price, and a second order will wind up being met from a different dealer's stock, one with a higher price. Noel

8 years, 4 months

Jump to page:

2025

2024

2023

2022

2021

2020

2019

2018

2017

2016

2015

2014

2013

2012

2011

2010

2009

2008

2007

2006

2005

2004

2003

2002

2001

2000

1999

1998

1997

test-drb