Ok, starting over here since there's been a long hiatus since the last
time I messed around with this.
I'm experimenting with different 8" disks trying to figure out what's
going on.
First, the basics: I know my controller can handle FM because I was able
to successfully copy all the files off an old 160K PC disk in my 1.2M
5.25" drive.
Second, the 8" drive can successfully format/read/write an 8" drive when I
have the BIOS configured for a 5.25" 1.2M drive. My drive is a Tandon TM
848-02. Someone e-mailed me a link to the manual they scanned, and now I
can't find that person's e-mail nor remember who it was (I'm so sorry!)
But at any rate, of the 3 measley links that come back from Google, I see
that this drive is DSDD. Still don't know if it can do FM however.
I have some 8" disks in both CP/M and DOS 2.11 format from my NEC APC.
They both read fine on the NEC APC.
I'm trying to read targeted sectors using debug.
With the CP/M disk, I try to L 0 0 0 1 (Load at address 0, drive 0, sector
0, 1 sector) and get:
Not ready reading drive A
Ok, so I try L 0 0 1 1 and after a longer pause get:
General failure reading drive A
Hmm, I'm still new to this, but this seems like a density issue.
Tried on the DOS 2.11 disk and got the exact same errors on both read
attempts.
I formatted an 8" disk under DOS, then tried L 0 0 0 1 from debug and
successfully load the sector into memory.
What's interesting is if I try to read sector 0 from the NEC DOS disk and
get the "Not ready reading drive A (Abort, Retry, Fail)" error, then
immediately put in my known readable formatted DOS disk and hit R)etry, I
get the same error ("Not ready reading drive A"). If I abort and then
retry, it works fine. Or if I wait at the Abort, Retry, Fail prompt for a
little while then retry, it also works.
Hmmm....
--
Sellam Ismail Vintage Computer Festival
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