Starting over with 8" drive on PC

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 ------------------------------------------------------------------------------ International Man of Intrigue and Danger http://www.vintage.org [ Old computing resources for business || Buy/Sell/Trade Vintage mputers ] [ and academia at www.VintageTech.com || at http://marketplace.vintage.org ]