17 Jul
2010
17 Jul
'10
10:43 p.m.
On Sat, 17 Jul 2010, Roger Holmes wrote:
It was only possible if you patched DOS RWTS by adding the driver and
geometry.
From: Steven
Hirsch <snhirsch at gmail.com>
Subject: Amlyn Minipac diskette changer
Has anyone else on the list seen one of these? I picked up a Vista V1200
disk system for Apple 2 that uses this type of drive. The mechanism takes
a plastic cartridge with five 5.25" floppy disks. The diskettes appear to
be conventional SS format with a couple of extra punchouts to mate with
the loader mechanism. Electrical interface is compatible with 8" floppy
drives (interface card was also sold for that purpose).
I'm not able to turn up any information about the drive and am wondering
how the diskette select/load scheme is intended to work. There are
at least a couple of possibilities:
- Treat the physical diskettes as portions of a single logical floppy and
select diskette by track range (first diskette 0-39, second 40-79, etc.)
- Treat each physical diskette as a logical drive and use binary select
lines on interface to choose.
Anyone have documentation on the drive mechanism or the Vista product?
I had a very similar unit for the Apple 3. As I remember it looked like
a single 6MB drive to the OS. I don't think that would have been
possible on Apple 2. Earlier I had a 5MB ICE hard drive on an Apple 2
which looked like 35 floppy disks to DOS. It might have looked different
under UCSD Pascal, maybe you could have a single large file, but its a
long time ago, I just can't remember.
There were many storage subsystems that extended the capacity of DOS 3.3.
Usually your choices of size were limited, however. The Sider was one of
the add-ons that supported this.
Steve
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