PDP-8 Discovery and Restoration

[Philippe Vachon]

Hi Folks.

Being a student of Engineering at Carleton University, every day I 
walked by an old PDP-8 that was on display in the halls. However, over 
the years it got bashed up and abused, since there was nothing 
protecting it.

Recently, I spoke to the chair of the department, and he (excitedly) 
agreed to provide me with space and the machine to restore, in hopes 
that the faculty could display it in its original glory (and even better 
if it is functional!).

I started the restoration this past Thursday. It shall be one hell of a 
job to say the least. The machine was on display for close to 20 years, 
I figure, and as such took quite a beating.

One of the parts in the worst condition is the bank of switches on the 
front. These were trashed by students walking by and playing around with 
them over the year.

So, the statistics for switches:

7 Brown Switches irreparable
4 White Switches irreparable

6 Brown Switches reparable
5 White Switches reparable

2 White Switches are perfectly intact
1 Brown Switch is perfectly intact

Also, unfortunately, certain flipchips (according to my schematics, 
anyways) are missing. The ADC option was installed, I know for sure, 
while the memory parity and power control stuff was not. At any rate, 
the first 11 flipchips from rows A and B on the processor side of things 
are missing in action.

The following flipchips are missing:

W501
R302 * 2
S603
R002 * 5
S111 * 9
R111
S603 * 2
S602 * 2
R405 * 2
S202
S203 * 2
S107 * 3
S151
R203
G209 * 3
R202 * 3
R503

The power supply unit for this machine has already blown in my face 
once, any advice on how to test/ensure that the PSU is functional?

I'm keeping a log of my progress at http://www.cowpig.ca and would 
appreciate any feedback people offer and any suggestions people have 
over the course of the project.

I'd really like to try to get this machine working. If anybody has any 
of the parts needed, and is willing to part with them, I would greatly 
appreciate it!

Regards,
Phil.