On 12/4/13 9:16 AM, Marc Howard wrote: I just uploaded MP00140_BA8-C_Unit_Assembly_Sep76.pdf 20 slot box drawings to bitsavers. It should show up on the mirrors in a couple hours.

The 8A500 drawing set is uploaded now, which has the drawings for the MM8

That seams to be right! Thank you. It might be set up for remote power control. Didn't know about this. I'll see if I can find anything that can confirm this. I don't have the rack and the drives home yet, but I'll have a look this weekend. I know that the computer is set up for 230V, which is good since I live in Sweden and have 230V power system. On page 60 in http://bitsavers.informatik.uni-stuttgart.de/pdf/dec/pdp8/pdp8a/PDP8A_Schem… the "Power distribution board control" is described. The drawing has number G8019-0-1. Thanks, I'll know that it will be hard, I have a programmers console on my wish list for this Christmas... /Anders ----- No virus found in this message. Checked by AVG - www.avg.com Version: 2012.0.2247 / Virus Database: 3658/6393 - Release Date: 12/05/13

Charles Morris and I that did some PCBs for replacement 8A programmer's panels. He got his working, but I ended up getting an original, so while my prototype got built, it never got debugged.... Once those were worked out, the boards worked. They are a pair, mounted back-to-back, each replacing one side of the original pair. Anyway, I think I have a few more PCBs, if you are interested. I think I also have some stock for the buttons, LED digits, and a few of the more exotic (LS367 and LED drivers, IIRC) ICs.

I think there was also some front panel work on laying out the artwork. I used a cardboard mock-up printed on my inkjet, but I think Charles ordered one from FP Express. I'd have to check my records. (That, of course, would be the single most expensive part.)

From: anders at abc80.net Wednesday, December 04, 2013 12:00 PM Charles Morris and I that did some PCBs for replacement 8A programmer's panels. He got his working, but I ended up getting an original, so while my prototype got built, it never got debugged. As I recall, the issues were with the power and ground planes (those boards have some very long power runs, and they were ringing a bit), and a consistency issue with the naming of pins on the interconnect between the boards (one drawing has bit 0 as LSB, the other as MSB). Once those were worked out, the boards worked. They are a pair, mounted back-to-back, each replacing one side of the original pair. Anyway, I think I have a few more PCBs, if you are interested. I think I also have some stock for the buttons, LED digits, and a few of the more exotic (LS367 and LED drivers, IIRC) ICs. I think there was also some front panel work on laying out the artwork. I used a cardboard mock-up printed on my inkjet, but I think Charles ordered one from FP Express. I'd have to check my records. (That, of course, would be the single most expensive part.) Oh, here's a link to a picture of Charles' panel: http://i1181.photobucket.com/albums/x426/DrCharlesMorris/PDP8A.jpg Vince

On Wed, Dec 4, 2013 at 12:16 PM, Marc Howard <cramcram at gmail.com> wrote: In my experience, *most* PDP-8/a units have only the minimal function (3-switch) front panel. I ended up buying one a few years back from a fellow collector just to have it for helping to diagnose faulty boards (plus I always wanted one for the "cool factor"). I always had at least an RX8E and RX01/RX02 on any -8/a, which was an entry level system back in the day. You could boot them from paper tape, but I don't believe that was commonly done much after 1980. The real trick now is if you have older boot PROMs and a newer boot device (RL8A) and finding replacement PROMs. ISTR blanks are $5-$8 each now, and you need a blaster that can do bi-polar devices. (Lyle Bickley provided a link to the newest ROM images on his own site via this message http://www.classiccmp.org/pipermail/cctech/2010-July/076991.html ) While you _can_ run older paper-tape software on an -8/a, they were largely configured and sold with the expectation of running OS/8 from floppy or hard disk. Not exclusively by any means, but primarily. As with earlier discussions about KM8AA boot PROMs, I can't seem to easily find the relevant tables of which PROMs support what devices. I *think* there is a paper-tape loader in at least one of them, but I'm having problems verifying that. I know it's documented in at least one of the printsets, but I can't recall where. It wouldn't be hard to rig up a modern computer to emulate paper tape and feed a machine that way (though you'd have to set the console SLU to something other than 110 bps if you wanted to use a bog-standard USB-serial dongle). -ethan