19 Jul
2010
19 Jul
'10
5 a.m.
On Sun, 18 Jul 2010, Steven Hirsch wrote:
<sigh>.. It appears that the OEM Amlyn diskettes are pre-formatted in
some manner.
I found a utility (from my Vista 8" Apple subsystem) that recognized the
data on my Amlyn drive cartridge and was able to retrieve the system
generation and format utilities. The latter works fine on one of the
cartridge diskettes, so I tried it on a blank 1.2M HD floppy that was cut
up to fit the unit.
The new disk loads properly without mechanical issues, but will not format
or otherwise show signs of life. I'm guessing they wanted to preserve a
market for blank diskettes and cartridges. Reminds me of the DEC Rainbow
(wasn't that system deliberately crippled to prevent it from being able to
format blank media?).
Steve
--
On 17 Jul 2010
at 16:16, Steven Hirsch wrote:
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. 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.