Well I’m now inline with a data tap, so I have access to all 25 pins on the floppy interface between the amiga and the floppy drive. I used to attach to the DB23 on the pass-thru port of the floppy drive, but I wanted to get in the middle.
Looking at the various pins with my scope, though, I can’t seem to locate the step pin properly. It’s supposed to be pin 18 on the DB23, or pin 19 on a DB25(since we skip pin 13) — but scoping that pin shows absolutely NOTHING happening.
Tim: if you are watching, how wide was the step pulse you were seeing coming from the amiga? And are there any serious discrepencies regarding the published pinouts? I have several sources, and they all line up.
On at least one of the pins, I see this pulse that seems to change pulse width. I either get a 8ms pulse or a 27+ms pulse. Measured something like 234ms apart.
I’m going to keep playing around…..