test-drb September 2016

test-drb@ccmp.vtda.org

162 participants
227 discussions

by ethan.dicks＠gmail.com

Hi, All, I've finally tracked down the simplest problems in my PDP-11/04 that's been sitting unused for many years (the one that we formerly used as a hardware test platform for Unibus COMBOARDs 30 years ago). The primary faults were a half-bad 7474 in the console (the flip-flop attached to the Run LED was not toggling when it should) _and_ an apparently bad DL11-W that isn't passing grant - for now replaced with a fully-functional module, but to be debugged later). What's happening now, since I can finally enter octal at the console, is when I change one location, 000000 for example, it echoes across multiple locations... To whit: I use the console to fill 000000 to 000040 with zeros, and verify they are all zeros. I deposit 177777 in 000000 and I get back the following... @L 1000 @D 177777 @L 1000 @E 001000 177777 @E 001002 004000 @E 001004 004000 @E 001006 004000 @E 001010 004000 @E 001012 004000 @E 001014 004000 @E 001016 004000 @E 001020 177777 @E 001022 004000 @E 001024 004000 @E 001026 004000 @E 001030 004000 @E 001032 004000 @E 001034 004000 @E 001036 004000 @E 001040 004000 @E 001042 177773 @E 001044 177777 I replace the 000000 at 000000 and get all zeros. So I appear to have two problems: 1) Depositing any value is echoed 000020 later. 2) Setting D10 in location 000000 results in D10 set in all the locations I have few spares for this machine. Lots of spares for my 11/34 (which I will want to test at some point soon), but this box (BA11-L) has a DD11DK not a DD11-PK, so I can't just upgrade in place. Does this sound like a dodgy CPU, dodgy RAM or both? I have this minimally loaded... M7263 PDP-11/04 processor M7847 16K MOS RAM (half loaded) M9312 with console ROM and papertape boot ROM (I have more ROMs available) M7856 - DL11-W strapped to defaults as a console/RTC many dual-height grant cards M9302 terminator UA-11 debugging board Oh... and I see while typing that it just started halting immediately after reset... so something just broke while it was powered on and running the console ODT. :-( I guess I'm back to low-level hardware debugging again. But in the meantime, any CPU/RAM symptom suggestions? I have the prints. I'm just looking for any "oh, yeah! That happened to me!" with "...and I fixed it by testing X and replacing the bad ones". All this so I can make a test bed for my M9313 boards and get them working again to fix the DWBUA on my VAX 8300... -ethan

9 years, 1 month

Discovery 500

by aek＠bitsavers.org

something of interest if you're in the Phoenix area www.ebay.com/itm/291860761669

9 years, 1 month

Manx

by COURYHOUSE＠aol.com

were you able to pull up link at archive.org ok I listed re: the terminals site is still on archive.org https://web.archive.org/web/20150720142308/http://terminals.classiccmp.org/w iki/index.php/Category:Alpha_Micro ta da...... Ed# In a message dated 9/6/2016 12:50:36 P.M. US Mountain Standard Time, pontus at Update.UU.SE writes: On Tue, Sep 06, 2016 at 08:01:17AM -0500, Jay West wrote: > > I did my best..... > I had no idea, thanks for all the extra work you put in for us. And a thanks to the maintainer of Manx for working with on it! It's a great resource. /P

9 years, 1 month

Manx

by jwest＠classiccmp.org

It was written.... ------------------------------- > but Manx seems to be in the process of being relocated > Hasn't Manx been in that state for ages? /P --------------------------------- manx.classiccmp.org terminals.classiccmp.org computergraphicsmuseum.com/net/org The owner of those three sites has the unfortunate honor of being the only person ever asked to leave the free hosting at classiccmp.org. I gave him 30 days to get his stuff hosted elsewhere. I even backed up all his content and databases and put them on a 1.5TB external hard drive and shipped it to him (while keeping the sites running on the classiccmp server). Even though I told him 30 days, I gave him about 180 days before I said "you have to get these moved or I'll have to turn them off". After about another 90 days or more, I did redirects back to his home site so they at least weren't dead. The content and databases are still on the classiccmp server, although publicly inaccessible, just to make sure the new locations are up and running before I delete the content locally. I did my best..... J

9 years, 1 month

RK05 packs

by jnc＠mercury.lcs.mit.edu

> So I have a fairly large group of 16-sector RK05 packs ... which I have > no use for, which I would like to trade for 12-sector RK05 packs Hi, all, I've had quite a few responses, so I think I have this covered now. Thanks to everyone who responded; if you haven't gotten a reply yet, I'm trying to catch up, you should hear soon! :-) Noel

9 years, 1 month

The huge lot that had the NIB 8" floppies is now on ebay

by sales＠elecplus.com

http://www.ebay.com/itm/-/191960867958 Apparently the buyer backed out, and the entire lot is now available as ONE lot. There is no reserve. Cindy Croxton

9 years, 1 month

Manx

by COURYHOUSE＠aol.com

the terminals site is still on archive.org https://web.archive.org/web/20150720142308/http://terminals.classiccmp.org/w iki/index.php/Category:Alpha_Micro ta da...... Ed# resending got error In a message dated 9/6/2016 9:07:15 A.M. US Mountain Standard Time, COURYHOUSE at aol.com writes: the terminals site is still on archive.org https://web.archive.org/web/20150720142308/http://terminals.classiccmp.org/w iki/index.php/Category:Alpha_Micro ta da...... Ed# In a message dated 9/6/2016 6:01:32 A.M. US Mountain Standard Time, jwest at classiccmp.org writes: It was written.... ------------------------------- > but Manx seems to be in the process of being relocated > Hasn't Manx been in that state for ages? /P --------------------------------- manx.classiccmp.org terminals.classiccmp.org computergraphicsmuseum.com/net/org The owner of those three sites has the unfortunate honor of being the only person ever asked to leave the free hosting at classiccmp.org. I gave him 30 days to get his stuff hosted elsewhere. I even backed up all his content and databases and put them on a 1.5TB external hard drive and shipped it to him (while keeping the sites running on the classiccmp server). Even though I told him 30 days, I gave him about 180 days before I said "you have to get these moved or I'll have to turn them off". After about another 90 days or more, I did redirects back to his home site so they at least weren't dead. The content and databases are still on the classiccmp server, although publicly inaccessible, just to make sure the new locations are up and running before I delete the content locally. I did my best..... J

9 years, 1 month

Manx

by COURYHOUSE＠aol.com

the terminals site is still on archive.org https://web.archive.org/web/20150720142308/http://terminals.classiccmp.org/w iki/index.php/Category:Alpha_Micro ta da...... Ed# In a message dated 9/6/2016 6:01:32 A.M. US Mountain Standard Time, jwest at classiccmp.org writes: It was written.... ------------------------------- > but Manx seems to be in the process of being relocated > Hasn't Manx been in that state for ages? /P --------------------------------- manx.classiccmp.org terminals.classiccmp.org computergraphicsmuseum.com/net/org The owner of those three sites has the unfortunate honor of being the only person ever asked to leave the free hosting at classiccmp.org. I gave him 30 days to get his stuff hosted elsewhere. I even backed up all his content and databases and put them on a 1.5TB external hard drive and shipped it to him (while keeping the sites running on the classiccmp server). Even though I told him 30 days, I gave him about 180 days before I said "you have to get these moved or I'll have to turn them off". After about another 90 days or more, I did redirects back to his home site so they at least weren't dead. The content and databases are still on the classiccmp server, although publicly inaccessible, just to make sure the new locations are up and running before I delete the content locally. I did my best..... J

9 years, 1 month

The huge lot that had the NIB 8" floppies is now on ebay

by cctalk＠beyondthepale.ie

Noel Chiappa wrote: > > > when folks just dump an ebay item number rather than a full link, those > > posts should die > > Why? It's a tiny bit more work to use them (prepend the number with the > string "http://www.ebay.com/itm/", and away you go), so one can't just click > and go, but are people really that unwilling to go to the slightest effort? > Any given posting to a mailing list is sent by one person and read by many. If there is a small effort to be made, it makes more sense for the sender to make it once than all the interested recipients to have to duplicate the effort. On the other hand, faulty spam filters may be more likely to stomp on messages containing urls so there may be also be a case for not including urls in postings if possible. Regards, Peter Coghlan.

9 years, 1 month

PDP-8 core memory problems.

by mattislind＠gmail.com

For some time I have slowly been working on restoring our PDP-8 to operating condition. Here are some notes on the progress: http://www.datormuseum.se/computers/digital-equipment-corporation/pdp-8 It is sort of working now after reforming capacitors in the PSU, adjusting memory currents and replacing a 2N3639 in a MA, MB, PC (R211) board. But bit seven is still showing a 0 when trying to set it. I found an old note that I wrote somewhere in 1990 that indicated the same problem was present then as well so it hasn't happen lately. I have now concluded that the fault is in the core memory module itself. The sense winding is broken on bit plane 7. So what are my options? What are the chances that a repair is successful? It looks really complex to take it appart and get to to layer seven. Then to find the broken wire, somehow replace it and splice it together with the rest of the sense winding... Not an everyday job. Does anyone have a known good spare module? I have some MM15 modules for PDP-15 to trade with! Could a MM15 module be adapted to be used instead? It is completely different foot print and it is a three wire stack. The Russian stacks sold on Ebay? But what guarantees are that those work at all and can be adapted... Probably other memory currents and cycle time? Some other technology that can be used to make up for the missing bit plane. But what technology and how. With as little intrusion in the machine. I don't really want to replace the entire memory system with a battery backed SRAM... Any ideas, thoughts or a working PDP-8 core memory module is highly sought for! /Mattis

9 years, 1 month

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test-drb September 2016