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I believe I was triggering on /START, but I now am of the opinion that that wouldn't tell me much useful, triggering on /RESET would be better. I also believe the "activity" we're seeing around the rising edges is just spurious glitches from slow rise times on the signals. To try to combat...

I grabbed a few traces on the logic analyzer, focusing on several pins on the controller Z8, Lizzy. If I understand what I'm seeing, it looks like it falls over almost immediately after coming out of reset, and never really gets the serial comms to the servo board up and running. Both Lizzys I...

I received a second (obviously nonworking) Widget drive today. As a quick check I swapped controller boards and the macroscopic behavior was indistinguishable, so I suspect my Lizzy is probably fine. This new-to-me drive does not even spin up, though, and I believe I hear a rattle inside when...

I have the Z8 with only the internal mask ROM ("Lizzy"). Having a piggyback one would be nice, but the only seller I can find them at is Vintage Micros and they want more than would like to spend. I started thinking about how to make a board with a ROMless Z8, a regular EPROM and a...

There was a single bit difference between my ROM dump and the image I found on Bitsavers. So, I burned a new one which of course didn’t substantially change the behavior. I “ll see if I can source some 6116 SRAMs but I don”t see anything compelling probing around it. I also measured my motor...

I started trying to work with NeoWidEx, but the system freezes when I try to do almost anything. I am now fairly consistently getting error 85 and the BUSY line is always asserted and never goes low. Looking at the Z8 firmware this is all consistent with something failing a test very early on...

Thanks for the response! I skimmed the boot ROM assembly code and it looks like the logic for generating these is quite simple. Error 81 is generated when a wait loop expires after ~100 seconds without BUSY going low. If BUSY does go low, we proceed to the check for error 82. It asserts the...

I've been working through my first Lisa 2/10 and have the machine working well enough to want to try using the Widget drive. I've gotten through many of the common issues. It initially was reticent about spinning up and was noisy, but after considerable cleaning and prodding it now spins up...