Received: from BULLDOG.CS.YALE.EDU by BUGS.SYSTEMSY.CS.YALE.EDU via SMTP; Tue, 19 Jan 1993 17:32:27 -0500 Received: from life.ai.mit.edu by bulldog.CS.YALE.EDU via SMTP; Tue, 19 Jan 1993 17:32:12 -0500 Received: from ns-mx.uiowa.edu by life.ai.mit.edu (4.1/AI-4.10) id AA00401; Tue, 19 Jan 93 16:41:33 EST Received: from pyrite.cs.uiowa.edu by ns-mx.uiowa.edu (5.64.jnf/920408) on Tue, 19 Jan 93 15:41:30 -0600 id AA03625 with SMTP Received: by pyrite.cs.uiowa.edu (5.59/890218) on Tue, 19 Jan 93 15:29:54 CST id AA12404 Date: Tue, 19 Jan 93 15:29:54 CST From: Douglas W. Jones Message-Id: <9301192129.AA12404@pyrite.cs.uiowa.edu> To: pdp8-lovers@ai.mit.edu Subject: PDP-8/M/F front panel Date: Tue, 19 Jan 93 15:29:54 CST From: Douglas W. Jones To: pdp8-lovers@ai.mit.edu Subject: PDP-8/M/F front panel I've just gotten down to work debugging the front panel on my second hand PDP-8/F. 3 of the LED's won't go out (and one more won't go on) in the data row. The problem is in the 74L54 chips that are used to multiplex the data for the data lights. I can't get 74L54 chips, but I can get 74LS54 chips, these have the right pinout, and more importantly, three of the 74L54 chips have already been replaced with 74LS54 chips. So, I verified that the problem is indeed in those chips by replacing one, and now I have to wait for 3 more (since I bought the last one in stock from the electronics place near my office. But, my question is, what is the problem with the 74L54 chips in the 8/F front panel? I'm replacing 4, and three others have been replaced some time ago. Did DEC screw up when they selected this chip? Is there something dangerous about the way it is driven that tends to burn it up? By way of information, the symptom I'm getting is an output that goes from 2.5 to 4.5 volts as the inputs change, instead of 0.3 to 4.5 volts (more normal). This suggests a blown output transistor, as if the chip tried to sink too much current at some time (difficult to do, considering that it only drives a 7404 chip). A second question is, does anyone know of a source of 74L54 chips? The 74LS54 seems to work, but it would be nice to use the right part if I could get one. The 74LS54 loads its inputs just slightly more than the 74L54, and one of the inputs is the DATA bus, so this could matter in a fully configured system. Any experience or warnings about this would be appreciated. Doug Jones jones@cs.uiowa.edu Received: from ELI.CS.YALE.EDU by BUGS.SYSTEMSY.CS.YALE.EDU via SMTP; Tue, 19 Jan 1993 22:21:22 -0500 Received: from life.ai.mit.edu by eli.CS.YALE.EDU via SMTP; Tue, 19 Jan 1993 22:21:11 -0500 Received: from opus.starlab.csc.com by life.ai.mit.edu (4.1/AI-4.10) id AA12795; Tue, 19 Jan 93 21:45:57 EST Received: by opus.starlab.csc.com (4.1/SunOS-RJD-1.07) id AA06897; Tue, 19 Jan 93 21:42:06 EST From: rmsmith@opus.starlab.csc.com (Robert Smith) Message-Id: <9301200242.AA06897@opus.starlab.csc.com> Subject: Re: PDP-8/M/F front panel (fwd) reply To: pdp8-lovers@ai.mit.edu Date: Tue, 19 Jan 93 21:42:05 EST X-Mailer: ELM [version 2.3 PL11] From: rmsmith@opus.starlab.csc.com (Robert Smith) Subject: Re: PDP-8/M/F front panel (fwd) reply To: pdp8-lovers@ai.mit.edu Date: Tue, 19 Jan 93 21:42:05 EST X-Mailer: ELM [version 2.3 PL11] Forwarded message: From rmsmith Tue Jan 19 21:40:27 1993 From: rmsmith (Robert Smith) Message-Id: <9301200240.AA06881@opus.starlab.csc.com> Subject: Re: PDP-8/M/F front panel To: jones@pyrite.cs.uiowa.edu (Douglas W. Jones) Date: Tue, 19 Jan 93 21:40:09 EST In-Reply-To: <9301192129.AA12404@pyrite.cs.uiowa.edu>; from "Douglas W. Jones" at Jan 19, 93 3:29 pm X-Mailer: ELM [version 2.3 PL11] Doug, Back in the days of the omnibus, Louie Klotz (mostly) and Remo Vogelsang changed the timing on me a couple of times. The loads on the bus, with the PROGRAMMER'S CONSOLE installed were a concern cause of guys like me designing i/o devices. The LED console, I don't remember who redesigned it from the lamps, was intended to be more reliable and produce less loads on fully loaded 8/e systems....we thought a big system was a two box four omnibus system.....that is two 8/e boxes. If you are not fully loading the omnibus, and you are not running one of the prototype kk8/e processors, with all the green wires like univ of colorado had on the mariner project, it won't effect your system. Someone might say it is not a pure system, but you can counter that with the fact that you can't find the date codes. Only a few chips were critical in the system if I remember correctly. On the EAE and I think there was one other peripheral..... hope this helps....bob Received: from ELI.CS.YALE.EDU by BUGS.SYSTEMSY.CS.YALE.EDU via SMTP; Wed, 27 Jan 1993 15:40:35 -0500 Received: from life.ai.mit.edu by eli.CS.YALE.EDU via SMTP; Wed, 27 Jan 1993 15:40:02 -0500 Received: from SSD.intel.com by life.ai.mit.edu (4.1/AI-4.10) id AA19124; Wed, 27 Jan 93 14:41:31 EST Received: from nautilus.ssd.intel.com by SSD.intel.com (4.1/SMI-4.1) id AA14748; Wed, 27 Jan 93 11:40:56 PST Message-Id: <9301271940.AA14748@SSD.intel.com> To: "Douglas W. Jones" Cc: prp@ssd.intel.com, pdp8-lovers@ai.mit.edu Subject: Module locations and power up hints In-Reply-To: Your message of "Mon, 25 Jan 93 13:40:06 CST." <9301251940.AA01338@pyrite.cs.uiowa.edu> Date: Wed, 27 Jan 93 11:39:53 -0800 From: prp@ssd.intel.com To: "Douglas W. Jones" Cc: prp@ssd.intel.com, pdp8-lovers@ai.mit.edu Subject: Module locations and power up hints In-Reply-To: Your message of "Mon, 25 Jan 93 13:40:06 CST." <9301251940.AA01338@pyrite.cs.uiowa.edu> Date: Wed, 27 Jan 93 11:39:53 -0800 From: prp@ssd.intel.com > You have a PDP-8? The original kind? Would you do me a favor and see > if there are any differences between the module maps in the maintenance > manuals I sent and the module layout in your -8. We have a few differences, > and before I turn it on, I want to know if they're misplaced boards or if > they're normal. > Doug Jones > jones@cs.uiowa.edu There are no interesting differences between the module layout in the maintenance manual and my PDP-8. One dual flip-flop module in the memory is blue instead of red, but its in the right place. Several modules shown as R in the manual are S in my machine, most often S111 instead of R111. My machine has a fairly low serial number, maybe around 250. The real serial number plate is missing, but some of the chassis plates are around that, and the core box is emi s/n 96. It has no options whatsoever. Not even data break. So of course I couldn't check positions of any modules which are in options. Since your machine's serial number is apparently 85, I would expect it to match the module locations fairly well. I would be careful about moving anything. Maybe you should spot check signal wiring in the suspect slots before deciding what to do. If you haven't powered it up yet, and its been in storage for many years, you might want to bring the voltages up slowly to give the power supply caps a chance to reform. This is more of an issue with high voltage electrolytics, but I have heard of flakey low voltage supplies that were powered up quickly. I did this with my PDP-8 the first time and have had no trouble with the power supply. I've recently done some testing on old high voltage caps, and recommend this sequence: Find a large enough variable transformer, and plug the computer into it. Turn the power all the way down and turn on the computer. Bring the voltage up slowly (I take up to half an hour, but that might be too conservative) to half voltage. Let it sit at half voltage for up to 24 hours (this is not particularly conservative - by my measurements, it takes many hours for the leakage current to drop.) Check the power supply for hot parts and turn it off if anything heats up too much. If its all OK, turn the power up slowly to full voltage. Check again for hot parts in the power supply. Also check around the memory. Reset the computer by pressing Start with Halt down, since the slow power up will confuse any power on reset circuit it might have. Enjoy! I think its probably OK for the processor to have half voltage on it, but if you are nervous about that disconnect the DC voltages from the power supply to the processor before doing the above. This also lets you use a smaller variable transformer. As far as I know, there aren't any critical electrolytics in the processor, you only have to form up the ones in the power supply. Be aware that some power supplies (especially switchers) don't like this treatment, but I think the PDP-8 supply is linear and will do fine. Have fun - Paul Received: from ELI.CS.YALE.EDU by BUGS.SYSTEMSY.CS.YALE.EDU via SMTP; Wed, 27 Jan 1993 17:25:15 -0500 Received: from life.ai.mit.edu by eli.CS.YALE.EDU via SMTP; Wed, 27 Jan 1993 17:25:03 -0500 Received: from Tomobiki-Cho.CAC.Washington.EDU by life.ai.mit.edu (4.1/AI-4.10) id AA24775; Wed, 27 Jan 93 16:38:59 EST Received: from Ikkoku-Kan.Panda.COM by Tomobiki-Cho.CAC.Washington.EDU (NX5.67c/UW-NDC Revision: 2.26 ) id AA12426; Wed, 27 Jan 93 13:38:56 -0800 Received: from localhost by Ikkoku-Kan.Panda.COM (NX5.67c/UW-NDC/Panda Revision: 2.27.MRC ) id AA02292; Wed, 27 Jan 93 13:38:50 -0800 Date: Wed, 27 Jan 1993 13:29:03 -0800 (PST) From: Mark Crispin Sender: Mark Crispin Subject: help in reviving a PDP-8 To: pdp8-lovers@ai.mit.edu Message-Id: Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Date: Wed, 27 Jan 1993 13:29:03 -0800 (PST) From: Mark Crispin Sender: Mark Crispin Subject: help in reviving a PDP-8 To: pdp8-lovers@ai.mit.edu Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII I have a PDP-8/e and PDP-8/f, neither of which are working. The 8/e never worked from the time I got it from salvage, and its main purpose in life has been to provide spare parts for the 8/f. The 8/f became cranky a couple of years ago when it would not run Focal properly; I have good reason to believe that the problem was in the TTY board's interrupt handling. Now, however, it isn't able to access memory at all; I just get zeros from any memory I read. I've already done all the obvious things (I was an 8 software hacker in the mid 1970's...). It's clear that the machine needs some hardware debugging, and it's beyond my expertise to do so (not to mention having other far higher projects to do). It's probably just a matter of a couple of chips from Radio Shack... Are there any competant 8 hardware hackers in the Seattle area who would like to take a look at it? Anyone who revives my little 8/f is welcome to spare parts from the 8/e (including the 8/e chassis). Oh. I didn't mention. The 8/e has a TU56. I would dearly love to get an OS/8 DECtape system going. I have no idea whether or not the TU56 works; nor whether any of the DECtapes I have are still readable. I *am* willing to throw money into this effort. Received: from ELI.CS.YALE.EDU by BUGS.SYSTEMSY.CS.YALE.EDU via SMTP; Wed, 27 Jan 1993 17:47:24 -0500 Received: from life.ai.mit.edu by eli.CS.YALE.EDU via SMTP; Wed, 27 Jan 1993 17:46:41 -0500 Received: from ns-mx.uiowa.edu by life.ai.mit.edu (4.1/AI-4.10) id AA26232; Wed, 27 Jan 93 17:02:15 EST Received: from pyrite.cs.uiowa.edu by ns-mx.uiowa.edu (5.64.jnf/920408) on Wed, 27 Jan 93 16:01:59 -0600 id AA25168 with SMTP Received: by pyrite.cs.uiowa.edu (5.59/890218) on Wed, 27 Jan 93 15:50:20 CST id AA04001 Date: Wed, 27 Jan 93 15:50:20 CST From: Douglas W. Jones Message-Id: <9301272150.AA04001@pyrite.cs.uiowa.edu> To: pdp8-lovers@ai.mit.edu Subject: mysterious box. Date: Wed, 27 Jan 93 15:50:20 CST From: Douglas W. Jones To: pdp8-lovers@ai.mit.edu Subject: mysterious box. A friend has been trying to get my help, by E-mail, in identifying a very dirty and very unloved DEC rack he found in a cluttered and dark basement Here's the current breakdown we've arrived at for the system configuration: _______ > |_______| > | Tape1 | < TU55 \ > | _____ | > serial numbers 2014 and 2078 > | Tape2 | < TU55 / missing some logic modules? > | _____ | > | empty | > | _____ | > | CPU | < Perhaps a PDP-8/S, but with no lights and switches > | _____ | just black panel with keyswitch in left corner. > | power | The machine seems to be made of S, R and G series logic. > | _____ | > | logic | < M series logic on the front of the rack, S, R and G > |_______| series logic on the back of the rack. Tape controller? > ||_____|| The key to the CPU type is that it has a backplane on top, with lots of red and green (by the light of a flashlight, so they could as well be blue) handles on the circuit boards as seen from below. It may not be a CPU for all we know at this point. The DIGITAL id plate on the back says BA08A/141, if someone can figure this out. The name "Astrotype" seems to be somewhere on or above the tape drives, suggesting that this may once have been an OEM'd system for some dedicated application, perhaps typesetting. Any ideas what we're dealing with? Doug Jones jones@cs.uiowa.edu Received: from ELI.CS.YALE.EDU by BUGS.SYSTEMSY.CS.YALE.EDU via SMTP; Thu, 28 Jan 1993 09:43:57 -0500 Received: from life.ai.mit.edu by eli.CS.YALE.EDU via SMTP; Thu, 28 Jan 1993 09:42:53 -0500 Received: from citi.umich.edu by life.ai.mit.edu (4.1/AI-4.10) id AA00854; Thu, 28 Jan 93 09:21:11 EST Message-Id: <9301281421.AA00854@life.ai.mit.edu> Received: from citi.umich.edu by citi.umich.edu with SMTP; Thu, 28 Jan 93 09:20:09 -0500 From: Sarr Blumson To: "Douglas W. Jones" Cc: pdp8-lovers@ai.mit.edu Date: Thu, 28 Jan 93 09:20:09 -0500 Subject: Re: mysterious box. In-Reply-To: Your message of Wed, 27 Jan 93 15:50:20 CST . <9301272150.AA04001@pyrite.cs.uiowa.edu> From: Sarr Blumson To: "Douglas W. Jones" Cc: pdp8-lovers@ai.mit.edu Date: Thu, 28 Jan 93 09:20:09 -0500 Subject: Re: mysterious box. In-Reply-To: Your message of Wed, 27 Jan 93 15:50:20 CST . <9301272150.AA04001@pyrite.cs.uiowa.edu> The key to the CPU type is that it has a backplane on top, with lots of red and green (by the light of a flashlight, so they could as well be blue) handles on the circuit boards as seen from below. It may not be a CPU for all we know at this point. The DIGITAL id plate on the back says BA08A/141, if someone can figure this out. I haven't even _seen_ a PDP-8 in almost 20 years, but isn't a BA09 a line printer controller? -------- Sarr Blumson sarr@citi.umich.edu voice: +1 313 764 0253 FAX: +1 313 763 4434 CITI/IFS, University of Michigan, 519 W William, Ann Arbor, MI 48103-4943 Received: from ELI.CS.YALE.EDU by BUGS.SYSTEMSY.CS.YALE.EDU via SMTP; Thu, 28 Jan 1993 13:04:46 -0500 Received: from life.ai.mit.edu by eli.CS.YALE.EDU via SMTP; Thu, 28 Jan 1993 13:04:38 -0500 Received: from ns-mx.uiowa.edu by life.ai.mit.edu (4.1/AI-4.10) id AA10654; Thu, 28 Jan 93 12:35:46 EST Received: from pyrite.cs.uiowa.edu by ns-mx.uiowa.edu (5.64.jnf/920408) on Thu, 28 Jan 93 11:35:43 -0600 id AA02792 with SMTP Received: by pyrite.cs.uiowa.edu (5.59/890218) on Thu, 28 Jan 93 11:24:03 CST id AA05070 Date: Thu, 28 Jan 93 11:24:03 CST From: Douglas W. Jones Message-Id: <9301281724.AA05070@pyrite.cs.uiowa.edu> To: pdp8-lovers@ai.mit.edu Subject: Help identify box, part II Date: Thu, 28 Jan 93 11:24:03 CST From: Douglas W. Jones To: pdp8-lovers@ai.mit.edu Subject: Help identify box, part II At this point, here's what we know we've found, covered with dust and long disused in a dark basement: _______ |_______| | Tape1 | < TU55 \ | _____ | > serial numbers 2014 and 2078 | Tape2 | < TU55 / missing some logic modules? | _____ | | empty | | _____ | | BA08A | < This is an expansion box for the PDP-8/L. | _____ | We don't know if it has 4K of core in it or not. | power | | _____ | | logic | < On the front of the rack is a BE01, behind it is a |_______| still unidentified collection of Flip Chips. ||_____|| So, what's a BE01? My friend has E-mailed me a module map for the BE01, in the hope that this would help pin it down. Working by poor light through dust, there may be some incorrect numbers here, particularly, some M203's might be M023's or the opposite. The cables up here go to the unidentified logic at the back of the cabinet. R c c c c c c c c c c c M M M M M M M M O a a a a a a a a a a a 6 6 6 6 6 6 6 9 W b b b b b b b b b b b 5 5 5 5 5 5 5 0 1 l l l l l l l l l l l 0 0 0 0 0 0 0 7 e e e e e e e e e e e R M M M M M M M M M M M M M M M M M M e e c c c c These O 5 5 5 5 5 5 5 5 6 6 6 6 6 6 6 6 9 1 m m a a a a cables W 0 0 0 0 0 0 0 0 5 5 5 5 5 5 5 5 0 0 p p b b b b connect 2 7 7 7 7 7 7 7 7 0 0 0 0 0 0 0 0 7 1 t t l l l l from y y e e e e row 2 to R w S S S M M M e C M M M M M M e M M M M M M M M M M M e c c c c row 3, O h 0 0 0 5 1 2 m 3 1 1 1 2 2 0 m 1 1 1 1 2 2 2 6 6 6 6 m a a a a there W i 4 4 4 0 1 0 p 2 1 6 0 0 0 6 p 1 1 1 1 0 0 0 2 2 1 1 p b b b b may be 3 t 0 0 0 1 3 3 t 0 1 1 1 3 3 2 t 7 3 3 3 1 1 3 3 3 7 7 t l l l l more e y y y e e e e of them. R e c S w M M M e C M M M M M M e M M M M M M M M M M M O m a 0 h 5 1 2 m 3 1 1 1 2 2 0 m 1 1 1 1 2 2 2 6 9 1 1 W p b 4 i 0 1 0 p 2 1 6 0 0 0 6 p 1 1 1 1 0 0 0 2 0 1 1 4 t l 0 t 1 3 3 t 0 1 1 1 3 3 2 t 7 3 3 3 1 1 3 3 7 7 3 y e e y y ^ | This cable is a thick cable, I don't know where it goes. All rows above are read from the handle sides of the boards. The cards labelled "S040" have no puller. There's no identification on the back of the chasis, where the cables from the first row connect. The back appears to have 4 1/2 rows, and most of the cables connect to the top half-row. Doug Jones jones@cs.uiowa.edu Received: from ELI.CS.YALE.EDU by BUGS.SYSTEMSY.CS.YALE.EDU via SMTP; Thu, 28 Jan 1993 14:29:35 -0500 Received: from life.ai.mit.edu by eli.CS.YALE.EDU via SMTP; Thu, 28 Jan 1993 14:29:32 -0500 Received: from MCIGATEWAY.MCIMail.com (MCIMAIL.COM) by life.ai.mit.edu (4.1/AI-4.10) id AA14321; Thu, 28 Jan 93 13:52:34 EST Received: from mcimail.com by MCIGATEWAY.MCIMail.com id at28142; 28 Jan 93 18:41 GMT Date: Thu, 28 Jan 93 18:43 GMT From: PJHurst <0005460443@mcimail.com> To: pdp8-list To: pdp8-list Subject: strange box Message-Id: <04930128184340/0005460443PK1EM@mcimail.com> Date: Thu, 28 Jan 93 18:43 GMT From: PJHurst <0005460443@mcimail.com> To: pdp8-list To: pdp8-list Subject: strange box If it was not for the serial number plate and r-series mods in the box i would say that you have a typeset-8 configuration with a 8/L CPU. Doug See if there are any serial number plates on the logic racks in the bottom of the box. Also is this mysterious rack, a old or new sytle cab? That is is the rack the old BUD tubular rack with treaded inserts to hold the logic (early 60's-late 60's use by DEC) or the newer type racks that dec used until a few years ago? Paul Hurst Salt-Ash Systems Chester, VT