test-drb February 2009

test-drb@ccmp.vtda.org

196 participants
309 discussions

by ethan.dicks＠gmail.com

Hi, All, I was one of the ones lucky enough to get one of the DEC Computer Labs on ePay last month. Mine finally showed up, and after a quick inspection, I'm ready to make some cables and hook up some circuits. Somewhere, I do have the teacher's manual. It was given to me nearly 30 years ago, a thoughtful gift from my step-dad's mother who was the local high school chem teacher. I haven't seen my copy in years, and I'm worried it was one of the things I lost in a basement flood in the 1980s. I did a google search and a look through bitsavers and didn't see anything to download, but I did see that this topic has come up on the list before. There was a call for scanning the docs some time back (6 years ago?) but no posting of where said scans might be. Also, there are Phillip's pictures of the cables on grid paper, so they look like pretty ordinary crimp pins, but I'm having to guess at the nominal diameter... 3mm? From the cover of the student manual, it looks like there are 25-ish of the shortest (brown) jumpers, and fewer of each longer length, but if anyone has a documented count of the number of each length of jumper wire, that'd be really nice to know. So are there scans of the student and teacher's manuals for the Computer Lab anywhere, and does anyone have a list (including in one of the manuals) of the normal inventory of jumper leads? Oh... one more thing... does anyone have any idea which bi-pin bulbs DEC used on this? I didn 't tear mine apart far enough tonight to get bulb details. Thanks, -ethan

15 years, 4 months

PDP 11/35 EIS option

by silvercreekvalley＠yahoo.com

Hi, Does anyone have a KE11-E (or KE11-F for that matter) available. This is a UNIBUS board for the PDP 11/35 or 11/40 which provides the extended instruction set. Part number is M7238 Thanks Ian.

15 years, 4 months

Powering up a 20-year old MicroVAX II

by gordonjcp＠gjcp.net

Robert Jarratt wrote: > The question is, could it be that I had not made the switch to 240 > correctly, or could this just be down to the age of the PSU? > Mains filter cap. Gordon

15 years, 4 months

Canon LPB-10 info sought.

by jos.mar＠bluewin.ch

I am looking for info on this very early (1979) laserprinter. In particular I need to know the electrical and software interface. Jos

15 years, 4 months

Searching for Disassembly pods for Tek 1230 Logic Analyzer

by ragooman＠comcast.net

Just wondering if anyone might know of any Disassembly pods for a Tek 1230 Logic Analyzer lying around somewhere. I keep searching the usual places online--but maybe someone knows a better place. I'm currently using the 6502 Disassembly pod and 48 channels, I like to try and get the Z80 pod or others if available. thanks =Dan -- [ = http://www2.applegate.org/~ragooman/ ]

15 years, 4 months

Powering up a 20-year old MicroVAX II

by ard＠p850ug1.demon.co.uk

> After removing all the boards and leaving just the disk and tape drive for > load I impetuously decided to try powering it up. I knew the PSU (model Personally, I'd not have used a disk drive (presumably a winchester-type hard disk) as a dummy load. If might well contain interesting software. But anywy, I would be very suprised if anything on the output side of the PSU has been damaged, > H7864) was set for 110V and made the switch to 240V (I am in the UK). When I > connected the power cord, after a few moments there was a loud pop, followed > by another before I could pull out the power cord, smoke rose from the PSU. > This sounded just like when I had once accidentally made a 110/240 mix-up. > > The question is, could it be that I had not made the switch to 240 > correctly, or could this just be down to the age of the PSU? I don't know the MicroVAX PSU that well (another list member wants me to dig mine out, take it apart and work out how to repair said PSU...) but my experience of DEC hardware is that if there's an obvious external voltage selector switch, that's all that needs to be changed. If there isn't (at least on older machines) there may be one or more sets of terminals inside to rewire. But I've never seen both. Of course on large systems there may be voltage selectors for each sub-unit (CPU, expansion box, drives, etc), but the Microvax II is in one cainet with one PSU. My guess is that it was just bad luck. Something in the PSU decided to fail. The next thign to do is to open up that PSU and see what has failed. Often it'll e obvious now. Look for burnt reisstors, exploded capacitors, blown PCB tracks, etc. -tony

15 years, 4 months

CiscoPro 761 ISDN router

by lproven＠gmail.com

Standalone ISDN to Ethernet router. Like a modern ADSL one, but this is for digital dialup. Handy for a relative with no ADSL coverage, perhaps? Bare unit - no PSU. Offered for free to anyone who will pay postage or can collect. -- Liam Proven ? Profile: http://www.linkedin.com/in/liamproven Email: lproven at cix.co.uk ? GMail/GoogleTalk/Orkut: lproven at gmail.com Tel: +44 20-8685-0498 ? Cell: +44 7939-087884 ? Fax: + 44 870-9151419 AOL/AIM/iChat, Yahoo & Skype: liamproven MSN: lproven at hotmail.com ? ICQ: 73187508

15 years, 4 months

Powering up a 20-year old MicroVAX II

by ajp166＠bellatlantic.net

> >Subject: RE: Powering up a 20-year old MicroVAX II > From: <arcarlini at iee.org> > Date: Sat, 21 Feb 2009 22:04:43 +0000 > To: "'General Discussion: On-Topic and Off-Topic Posts'" <cctalk at classiccmp.org> > >cctalk-bounces at classiccmp.org wrote: >> IMHO the most important thing to do after checking for >> obvious problems >> -- loose parts, evidence of overheating/burning, etc, is to test the >> power supply (PSU) on a dummy load. A defective PSU could >> wipe out every >> chip in the machine!. > >In addition, pay particular attention to the PSU wiring harness. > >The early rev of harness on (iirc) the BA23 had a habit of >catching light. I think it was slightly underrated for the >maximum power load and so would deteriorate over time. It >would eventually reach the point where one of the N conductors >would fail, leaving N-1 carrying way too much load and smoke >ensued. > Correct the worng harness has unequal length wires and the correct one has equal length wires. The harness in question goes from the Backplane to the PS. The problem is with unequal length wires the connectors were sharing the load unequaly and the connecotr would overheat and fail sequentially. It was more of a problem on highly loaded boxes. >Field service were (again, iirc) supposed to swap these out if >they came across them. But if your machine has truly not been used >for twenty years, it ended up in storage relatively eraly in its >life and so may not have had a chance for some FS TLC. 20 years is maybe on the wire. It may have been already replaced. > >A little bit of googling should find you the relevant details >(or you could wait for the next post which will no doubt be >from someone with much better memory than me :-)). > >The only other thing I would add to Tony's post is that once >you think it isn't going to fry your boards (or burst into flames) >then you only need the CPU and one memory board in. Then you hook >up a terminal to the console (9600-8-N), set the switch properly >and check that you get some kind of life on the console. It doesnt bust into flames, it can overheat to the extent of destroying the connectors and smoke some. In this day and age cookingthe backplane connector is a real pain as spares are getting scarce. Allison >At that point you can start to add the remaining boards (checking >that Qbus grant continuity is OK as you go) and build your system >back up again. > >There are plenty of docs you can track down on Manx >(http:://vt100.net/manx). >You can google for the various Micronotes too, some of them are relevant >to the MicroVAX, others to the Qbus, and all of them are interesting >background reading. > >Antonio >arcarlini at iee.org > >

15 years, 4 months

WTS: AT&T 3B1 Olivetti branded with manuals and DEC Vaxstation 2000 storage box.

by hp-fix＠xs4all.nl

I'm concentrating my collection on HP, so before I put it on epay: I want to sell or trade my working AT&T 3B1 Unix PC this one is co-branded with the Olivetti logo. I'm selling it together with 5 manuals and the original installation software (only disk two diagdisk is missing) The 3B1 is equiped with the DOS73 Co-processor board. Also I'm selling a VaxStation 2000 storage box inside is disc but I won't spin when power was applied. This could be a jumper issue but I sell it as non working. Photo's can be found at flickr http://www.flickr.com/photos/35618294 at N03/ Please contact me off-list . -Rik I'm located in the Netherlands.

15 years, 4 months

Powering up a 20-year old MicroVAX II

by ard＠p850ug1.demon.co.uk

> > I have just collected a MicroVAX II which has been in storage and has not > been powered on for 20 years. This is my first machine of such an age, > unfortunately I am not particularly knowledgeable at the electronics level > (I studied circuits academically 25+ years ago and can solder a bit, but > that is as far as it goes). I know I will need to treat it carefully in > order to get it working again. I plan to open it up and make sure I clear > out any debris etc, but beyond that I need advice from those with the > experience and knowledge that I lack on how to go about powering it up > carefully. IMHO the most important thing to do after checking for obvious problems -- loose parts, evidence of overheating/burning, etc, is to test the power supply (PSU) on a dummy load. A defective PSU could wipe out every chip in the machine!. Since you're happy to dismantle the machine anyway, this should be quite easy. With all the PCBs out of the backplane (make notes/diagrams as to what goes where), and with the power cables unplugged from the drives, connect a 6V car bulb between the +5V line and the 0V line (you can find these by tracing back from the known Q-bus pinouts if you can't find them any other way) and power up. Mearue the 5V line with a voltmeter, and if possible the other power lines (if you can find them). Only when you know they're correct should you plug the logic boards in. Oh, I would recomend opening up the PSU (mains disconnected, of course), and looking for signs of trouble in there. And check all the fans are rotatig when you turn it all on -tony

15 years, 4 months

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test-drb February 2009