16 Aug
2025
16 Aug
'25
9:36 p.m.
Hi Tom
Grok tells me: “ Yes, the DEC PDP-8/S uses many of the same flip chip PCBs as the
original PDP-8 (Straight-8), particularly from the R-series Flip-Chip modules. Both
models rely on these standard R-series modules as building blocks for their
diode-transistor logic, though the PDP-8/S implements a serial architecture that reduces
the overall number required. ”
You should be able to find the R series schematics on line. If not, contact me on Brendan
at McNeill dot co dot NZ and I will share my PDF’s with you. I’m out of town for the next
couple of days.
Sent from my iPhone
On 17 Aug 2025, at 16:11, Tom Hunter via cctalk
<cctalk(a)classiccmp.org> wrote:
I have recently bought a DEC PDP-8/s. It hasn't been powered on for about
40 years before I got it. I cleaned it and did some repairs on it (glued
broken flip-chip handles, replaced all front panel lights, restored the
acrylic front panel to as new condition and built a new switch mode power
supply for +10V and -15V).
After testing each flip-chip individually for dead shorts on the power
rails I reassembled the flip-chips into the backplane and on power up it
shows signs of life, but has a number of problems I will have to debug and
fix.
Does anyone here have the original Engineering Drawings or good PDF scans
of the drawings?
There are reduced copies of the PDP-8/s Engineering Drawings in Appendix A
of the two PDP-8/s Maintenance Manuals on Bitsavers, but I have not been
able to find scans of the actual Engineering Drawings. Some details in the
reduced copies in Appendix A are not legible.
Thank you
Tom