Re: Using 3.5" Drives (or CFFA) with 5.25" DOS3.3 Disk Images Directly

[ferdimh@gmx.de]

On 19 Jan., 01:52, Warren Ernst <wer...@gmail.com> wrote:
> I've since been searching the archives via Google, and it seems as if
> my answer will be "not bloody likely." The various DOS 3.3's that work
> with 3.5" disks aren't easily readable by utilities like Copy II + or
> the Finder, so it doesn't seem likely that any disk decompression
> utility would either.
>
> I have been reading up on Glen Bredon's DOS Master and while it makes
> putting hundreds of DOS 3.3 volumes on a CF card with the CFFA, the
> processes of copying many games over looks torturous.
>
> But if anyone has any bright ideas, I'd love to hear them...
>
I'm working on 3.5'' drives which are compatible with the original
Disk ][. I have been using the prototype for about 2 months now,
without real problems. My original design is intended to be hooked up
to a normal Disk ][ interface card, but now I'm making a new
controller card, because it simplifies the design and because it
doesn't occupy the ports on the Disk ][  controller card (note that
3.5'' and 5.25'' drives can't be mixed!)
I expect to have the controller card working by the end of the next
month.
The format allows to store either
- one volume of 640KB (patched ProDOS only)
- two volumes of 320KB (patched DOS, patched ProDOS and patched
PASCAL)
- two volumes of 140KB (plain DOS, plain ProDOS, plain PASCAL)
- one copy protected disk (quarter-tracks aren't supported, and I
haven't tried any half-track schemes)
the two volumes can be selected by a switch.
A normal 3.5'' drive (shugart bus, intended for an IBM PC) can be
used, but it needs either a modification or an external read amp. I
have used several TEAC drives which work with the read amp I have, but
for other drives (e.g. panasonic) the read amp needs to be modified.
It might be possible to use an 800K Apple drive or a 720K Shugart
drive without modification, but I haven't tested it.
Setting up the read amp for an unknown drive isn't that difficult, but
requires an oscilloscope.
Support for ProDOS is still experimental. I'm still working on the
required tools (formatter, diskcopy etc).
If everything works fine, I'll let you know.

------
Ferdinand