pdp 8/e

From: Chuck McManis <cmcmanis_at_mcmanis.com>
Date: Wed Oct 6 15:58:32 1999

>Well, the pdp8/e power sord was cut off, but there is a 2 foot long hunk of
>wire. I suppose I'll just wire up a power connector, and they use a good
>quality extension cable (someday). No rush on that...

That's pretty easy to replace, make sure you use a heavy gauge.

>The core memory planes were removed, of course. Looks like there were at
>least 3 sets of core in this at one time. The foam along the side of the
>case has pretty much vaporized and is all over the bus connectors. Whats
>the general consensus (yeah right, on THIS mailing list i was a consensus...)
>about removing versis replacing that foam?

The foam helps keep the cards from knocking against each other. Thus it is
good to replace, it is also a good idea to remove the old foam and vaccum
out the back plane! Many times plugging a card into a slot that has foam
wedged in it gives bad results.

>And one front panel switch is gone, and another is present but broken. The
>rest at least appear to click up/down properly.

I've got a spare switches in the darker orange but may not have one in the
lighter yellow. Let me know if you'd like me to send them out to you.

Tell us, did you get the "long" box or the "short" box? (the long box has
two back planes in it connected by a row of jumpers.)

>Boards that were in my PDP8/e when I recieved it
>===============================================

This one is Timing/Control
>M8330

These two go next to it.
>M8310 Loose
>M8300 Loose

The sequence is M8330 M8310 M8300 (and if you get an M8340 and M8341 they
will go between the 8330 and the 8310) Normally they are connected across
the top with top connectors. These look like short two plug back planes. If
you don't have these see if you can go back and root around for them. In
the 8/e/f/m you need at least 6 (4 for memory, 2 for the CPU)

This one:
>M837

Gives you extended memory control, up to 8 "pages" for a total of 32K of
core. It isn't required to operate the machine but without it you are
limited to 4K of core.

This one:
>M8655

Is a serial port. (and the nicer one too!) You can run this one at RS-232
levels right into your PC at 4800 or 9600 baud. See comments on Doug Jones
and Aaron Nabil's sites for modifications and building cables.

These two:
>M8360
>M8350

Make up a positive bus interface and a DMA (data break) card.

>VG DS (dont know the number)

Another serial port:
>M8655

This one I'm drooling over:
>M840

This is the high speed paper tape interface. It connects to the PC04
reader/punch.

This one
>M849
is an RF shield it sits between the core stacks and the CPU to protect them
from stray magnetic fields that might perturb their bits.

This is:
>G111 Loose. 2 of these
>G233 Loose. 3 of these (too bad they didnt leave the core planes)
Parts for 2.5 8K core stacks. You need the H212 core mats to complete the
picture.

these indicate you got the "long" box yes?
>M935 2 of these, to connect the second bus

[snip]

These are the bus loads and go in the last slot.
>M8320

pretty clear what this does. Pretty cool though.
>M847 YH Bootstrap Loader (32 words implemented via an array of diodes)

All in all a pretty good catch. While it may be hard to get core for this
thing you can find MOS memory systems at various places. The thing to worry
about will be the top connectors. If you don't have them you can make them
but it isn't fun. Some folks on the pdp8-lovers list might have spares.

Other questions:
        What was the date of manufacture? (on the back by PSU)
        Is the front panel lamps or LEDs?

--Chuck
Received on Wed Oct 06 1999 - 15:58:32 BST