On Tue, 24 Sep 2024, Steve Lewis via cctalk wrote:
But does anyone here in the States happen to have a stack of known-good
5.25 disks they don't want anymore?
Sorry, not right now
have a drive for an old system that currently uses bubble memory
cartridges to boot to PC-DOS 2.0, and so we'd like to see if (using
these external drives) it could also boot to a (confirmed legit) image
of IBM PC-DOS (and/or very early Microsoft DOS). Or, do we still need
some kind of proprietary Sharp DOS image? (in which case, extra blank
disk would be good, as I think there are tools on these bubble memory
cartridges to initialize disks accordingly).
What kind of drive is it?
If it boots to PC-DOS 2.00, not MS-DOS 2.00, then it is not some kind of
proprietary Sharp DOS.
If Sharp, or whoever made your machine, ever did provide their own
customized MS-DOS, it was likely to be versions 1.25, 2.11, or 3.31
Many OEMs added 3.5 support in MS-DOS 2.00 amd 2.11. PC-DOS didn't
support 720K until PC-DOS 3.20, and 1.4M 2ith 3.30
(did anyone ever make a "USB-to-5.25" drive? I have a couple 3.5
versions of those - maybe the power to motor the 5.25 is too much for
USB? :D ).
a few minor problems, in addition to power (easily solved with a external
brick)
There did once exist a few, but they are VERY rare.
There were also some with cooperative circuitry, that had an unmodified
3.5 drive in them that could be recabled to 5.25.
(still a few gotchas to deal with, such as "Disk changed" signal)
But, if you have a functioning 720K 3.5, you could put early 5.25 DOS on
it, even down to 1.00, and just use the first 40 tracks. In the days
before the 5170, the machine didn't really care,
--
Grumpy Ol' Fred ci...@xenosoft.com
