From: Don Maslin <donm(a)cts.com>
The DD part sounds rather like what Altos used on their
8" DD disks,
and which no PC FDC that I know of can read. I doubt that they did
the SD header part though. Have to fire up my Sierra (Altos clone)
and see if it can read the RX02 stuff - or at least look at it with DU.
I bet the altos can't. The mixed density format is something only DEC
did.
Intel also used M2FM (rather than MFM) for double density for the 2xx
series
development systems. it was also incompatable with everything and
used 3000 series bit slice.
Allison