Chuck Guzis cclist at
Wed Feb 3 14:00:50 CST 2021

I'll add just a bit with respect to floppy disks on an MCU.

One reason to put histogram and peak-detection in the MCU firmware is
that for a disk you never know how far out of alignment the original
(recording) drive might be.  A drive used to record something out of
alignment can yield garbage on a blind capture.

A drive that allows for adjustment means that you can sample a track,
and adjust until you see nice clean peaks.   Blind-on-the-fly recovery
makes this a lot more difficult.  You can certainly add some primitive
decoding for FM, MFM, MMFM and a few varieties of GCR as a sanity check,
but looking at spectral peaks is a first-line diagnostic.


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