On 7 May 2007 at 6:29, Jules Richardson wrote:
Aren't hard-sectored 8" floppies available in
more than just 32 sectors/track
flavours? It's no big deal if your circuitry is analysing timing relationships
to detect index pulse, but it obviously is if the circuitry's relying on
timing windows as the timing will be different for a 32-sector disk versus one
with n sectors...
Yes, 8" disks also appear in 8 and 16 sector versions, although the 8-
sector ones are fairly uncommon. Many 8" drives that can take HS
media do so through a jumper settings on the drive board.
I've pushed MFM data through an SA-800 with no problems. I don't
keep the 800's around, however, as they're only single-sided and
don't seek very fast.
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About putting multiple drives on a single connector--some older
drives have removable pullups (usually 150 ohms); later ones have
lower-value builtin pullups. In any case, I'd limit the number of
drives on a single connector to 4. Two connectors driven by nice
beefy 50 ma OC drivers would make most people pretty happy, I'd
think.
Cheers,
Chuck