Reply 24420 of 25342, by Thermalwrong
Hmm, should've looked a bit closer at these SIMMs before I decided they were good candidates for upgrading to 1MB simms - Found out a little late that the A9 pin isn't wired up so had to run a new trace for it on each one:
This actually passes memtest 😀
Hopefully the epoxy coating on the magnet wire doesn't rub off since each wire runs through another signal's VIA to get to the otherside of the SIMM so that the signal is present on both sides.
But you'll notice the parity chips are missing and that's because the pinout for the HYB511000BJ-70 chips are somewhere between different and just not fully routed on this PCB. Had to run like 6 traces and pull up lots of pins to get parity to work so these are non-parity sticks. Which is fine, I had another set of 1MB SIMMs that are much more recent but didn't have parity chips fitted, now they do.