If possible, bring to a workshop? BIll On Mon, Sep 2, 2024 at 1:45 PM Mike Rieker via vcf-midatlantic < vcf-midatlantic@lists.vcfed.org> wrote:
Hi All,
I'm restoring a PDP-8/L. I got it mostly working, had to replace a couple chips.
Anyway so of course, the memory isn't reliable. I can deposit to some locations and they read back ok, but other locations do not. And which locations are good seems change from day to day though I'm not sure about that yet.
It is able to run a small loop (IAC / JMP .-1) seemingly for hours on end after hunting for some good memory locations, so the memory isn't a complete basket case. After all it is doing read/write cycles just to fetch instructions.
I have checked the supply voltages and there is a timing diagram in the PDP-8/L maint volume 1 book that seems ok. This one seems a little slow (like 600nS instead of 500nS), but the stuff seems to be in place, relative to each other. The manual shows some current waveforms to check but I don't have a current probe (one is on order). Anyone have experience getting this stuff to work?
Thanks, Mike Rieker