21 Apr
2000
21 Apr
'00
4:03 p.m.
On Fri, 21 Apr 2000, Fred Cisin (XenoSoft) wrote:
But MS-DOS does not use E5H and does use 00H fill in directory areas. I
suspect that this might confuse the CP/M-86 directory program a bit - a
whole bunch of null filled directory entries, all at user 0!
- don
On Fri, 21 Apr 2000, Tony Duell wrote:
Also, by not getting error messages, that it's finding the sector numbers
that it's looking for, therefore it has the expected number of bytes per
sector and range of sector numbers (do the numbers start at 0, 1, 20, ...)
I just checked, and the NEC 8" CP/M diskettes that i"ve seen have 256
bytes per sector; but not the MS-DOS ones, therefore I retract my previous
suggestion that these might be MS-DOS diskettes.
True, it is finding the sector numbers it is looking for, but it also is
finding E5H where it expects to find the user area number or there could
be either an error message or perhaps a garbaged directory display if it
found 00H by chance.
DIR but
they all come back with "NO FILE". Now of course this means
This
message is also telling you a couple of good (?) things. Firstly
that the drive/controller is managing to read valid sectors off the disk
(so the drive is working, the heads are clean enough to read something,
etc). Otherwise you'd be getting the well-known BDOS errors. And secondly
the directory makes some sense as a CP/M directory. At least
the system thinks it does, and it thinks its empty. So it's likely (not
certain ) that the disks are CP/M86 ones.
Definitely not CERTAIN. An empty CP/M directory is indistinguishable from
a blank formatted track, and similar to empty MS-DOS directory sectors. Since CP/M had reserved track(s), the CP/M directory
would miss the FAT,
and could easily occupy sectors at the end of an MS-DOS directory. MS
Stand-alone-BASIC, which was used on a lot of NEC products, but which I
haven't seen on the APC, had a directory similar to the Coco on a middle
track; the track used by CP/M for its directory could be empty. The NEC
8" CP/M diskettes that I've seen have had several different numbers of
reserved tracks; therefore it could be a CP/M format, but not the RIGHT
one.
I think one option to the STAT command (STAT
USERS, STAT [USERS] ???)
will tell you at least which user numbers have files on the disk
Do you have any communication with the makers of the disks? Is THEIR APC
working? If so, try STAT DSK: on both machines and compare.
--
Fred Cisin cisin(a)xenosoft.com
XenoSoft http://www.xenosoft.com
2210 Sixth St. (510) 644-9366
Berkeley, CA 94710-2219