On 10/11/2005 at 9:24 AM Sridhar Ayengar wrote:
How about SCSI floppy drives?
The problem with SCSI floppies is essentially the same--addressing is on a sector number
basis, not CHS. So the drives have limited format recognition capabilities. I've
never seen a 5.25' SCSI floppy, though at one time SMS marketed a SCSI-to-FDC
conversion board. But that was many years ago in the early days of SCSI, so it probably
wouldn't work on a modern SCSI adapter. Perhaps the SCSI firmware in a stock Teac
FD-235S could be tweaked, but the drives are pretty hard to come by.
Although a stock USB drive is pretty brain-dead, it should be noted that the SMSC USB
floppy chip (USB97CFDC2-01) does have the option of attaching a user-supplied external
serial EEPROM for custom support. According to the SMSC website, an evaluation board was
produced for the first version of this chip (USB97CFDC), and, judging from the schematic,
attached to a legacy floppy interface. It'd be interesting to get a couple of the
boards and see if the chip could be made to drive a 5.25" drive and how much
flexibility is incorporated in the chip (e.g., can FM-encoded diskettes be read?). Of
course, host-side drivers would have to be written to handle an expanded interface, but it
still might be an interesting exercise.
Cheers,
Chuck