I rewired the disk tool driver board to use one bidirectional level shifter chip, containing four independent circuits, for the three timing critical signals, plus swapping in CD4050 chips which operate at higher frequencies than the original CD4504 choices.
Ken is picking up a couple of extra disk cartridges from Xerox PARC, one of which I will use to test out the disk driver role. I am working toward using it on the next Alto restoration team meeting, probably on Friday.
With my new components in place, I did some stress testing of signals through the extender board. I still have to tweak the terminator resistors on my side to clean up the incoming signals a bit more. That done, I had good enough results at 3.2MHz to move forward with the board.
I don't have enough resistors to terminate all the incoming lines, requiring a trip to Anchor Electronics tomorrow before I finish off the board.