ISA would be fine. Basically I need something I can
hook up to a PC
(either my clunky old 386-with-ISA-IDE-controller or something more
recent) that will allow me to format the drive, and write something to
it. Bulk-erase by holding WR_GATE active and WR_DATA low and
track-stepping, then format using the controller. Read the data back
with the Ferret and see what's there (probably an MFM bitstream based on
the Seagate format recommendations).
My understanding is that there's enough variation in the low level
formatting between controllers that MFM drives aren't very portable.
That could be interpreted as timing differences between models, or as
timing variations in different instances of the same model, or even
actual structure differences. I don't know which was meant by whatever
source told me this long ago.
Even assuming it is true, it doesn't necessarily kill your concept,
though it might make implementation a hell of a lot more exciting.
De