C-128 CP/M MFM diskette formats supported
prindle@nadc
While peeking around in the CP/M BIOS (trying, with reasonable success, to
read MS-DOS diskettes with a public domain program called RDMS), I ran across
two additional diskette formats that the BIOS is keyed up to recognize: SLICER
and EPSON EURO. Anybody ever heard of one of these systems?
What I've been able to find out is that by poking the right values (ahh.. that's
the key - the *right* values) into the MFM Disk Format Table (as documented,
sort of, in the 128 PRG), you can make C-128 CP/M read just about any format.
There are spare slots in the table. The info you need for a diskette format
is bytes/sector, sectors/track, sides, where the allocation block and directory
blocks are, how the tracks and sectors are numbered, etc. Given all the
necessary info, it would seem that it would be a snap to write a sort of
"UNIFORM-128" program. The question is: where are all the 5.25 inch CP/M
diskette formats documented?
Sincerely,
Frank Prindle
Pri...@NADC.arpa
Rob Tillotson
> two additional diskette formats that the BIOS is keyed up to recognize: SLICER
> and EPSON EURO. Anybody ever heard of one of these systems?
>
on QX-10's distributed in Europe (the Epson people call it MFCP/M format).
According to an Epson user I know, the QX-10 reads all 3 formats for internal
compatibility, but the Euro format isn't very popular.
The Slicer, as far as I know, was a 8/16 bit micro that ran both CP/M
and MS-DOS. Nobody I've talked to has actually seen one, though, which
makes me wonder why they bothered to put it in the BIOS at all... perhaps
someone at Commodore had a Slicer disk laying around?
> What I've been able to find out is that by poking the right values (ahh.. that's
> the key - the *right* values) into the MFM Disk Format Table (as documented,
> sort of, in the 128 PRG), you can make C-128 CP/M read just about any format.
...
> necessary info, it would seem that it would be a snap to write a sort of
> "UNIFORM-128" program. The question is: where are all the 5.25 inch CP/M
> diskette formats documented?
>
Sorry, but I don't know. However, if you find out anything, please post
it... I am writing just such a program, but have paused because I don't
have data on any other formats. I suppose the best way to collect this
information is to ask owners of different machines for the details, or to
dissect a program like Uniform... I am sure that it works similarly to the
128's BIOS (i.e. changing the drive tables in RAM to the format you select)
so they should have a similar table somewhere in them.
Good luck.
> Frank Prindle
Rob Tillotson ...ihnp4!killer!sentinel
{anybigsite}!pur-ee!sentinel
sent...@el.purdue.edu
Dave Haynie
> In article <2...@rutgers.RUTGERS.EDU>, dae...@rutgers.UUCP writes:
>> two additional diskette formats that the BIOS is keyed up to recognize: SLICER
>> and EPSON EURO. Anybody ever heard of one of these systems?
>>
> and MS-DOS. Nobody I've talked to has actually seen one, though, which
> makes me wonder why they bothered to put it in the BIOS at all... perhaps
> someone at Commodore had a Slicer disk laying around?
Greg Berlin, hardware designer of the 1571, used to have a Slicer around. Its
a single board computer, which has the 8/16 bit 80186 chip on it. It was
originally set up to run with CPM-86, I believe, but later they came out
with MS-DOS ROMs. Anyway, that's probably where the Slicer format came
from; strange, I'd never heard of that being built in before.
>> Frank Prindle
>
> Rob Tillotson ...ihnp4!killer!sentinel
> {anybigsite}!pur-ee!sentinel
--
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Dave Haynie {caip,ihnp4,allegra,seismo}!cbmvax!daveh
"Laws to supress tend to strengthen what they would prohibit.
This is the fine point on which all the legal professions of
history have based their job security."
-Bene Gesserit Coda
These opinions are my own, though for a small fee they may be yours too.
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