On 17 Jul 2010
at 16:16, Steven Hirsch wrote:
I pulled down a copy of their patent application
for the unit and it
almost looks like the Minipac diskettes have some sort of pre-written
servo track. Perhaps the unit can actually write this servo, but
without documentation I'm just surmising.
Could be. It sounds a bit like the Drivetec drives of the same time
period. Something like (ISTR) 192 tpi, using an embedded servo,
making factory-formatted disks mandatory, something that probably did
more to kill the drive than anything else. I've still got a couple
of the Kodak/Drivetecs with media from Dysan, but basically they
exist for the eventuality that someone, somewhere has data written on
one of these that they need to get at.
Gets stranger as I go... I disassembled the drive to take a short at
cleaning the heads. Turns out to be "head" (singular). If the total
capacity is 6MB, then they were writing 160 tracks on a single side. That's
pushing the envelope for mechanical alignment on a floppy and certainly
explains why they used servo-feedback positioning instead of blind stepping
like a conventional drive. The majority of claims on the patent pertained to
track positioning, so this is all consistant.