Progress on NEC APC

From: Fred Cisin <>
Date: Fri Apr 21 14:12:21 2000

On Fri, 21 Apr 2000, Tony Duell wrote:
> > 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.

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.

> 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

> 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            
2210 Sixth St.                  (510) 644-9366
Berkeley, CA 94710-2219
Received on Fri Apr 21 2000 - 14:12:21 BST

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