The other day, I noted that both the DTC 3280 and the UltraStor 14N
SCSI controllers have an option to add a 3rd floppy drive to the
common floppy cable. Essentially, they place the motor control on
pin 4 and drive select on pin 6 for the extra drive. It's not hard
to make up a cable (Ultrastor supplied one with their kits) and a
simple DOS driver provides access to the third diskette. I have a
couple of drivers, if anyone's interested.
But I wanted to use a Future Domain 1670 controller in this case. It
uses the same FDC (National DP8473), but doesn't bring the motor and
drive select out to the floppy connector. So, for 5 minutes of time,
and a couple of lengths of wire wrap wire and a hot soldering iron,
all one need do is strap pin 4 of the floppy connect to pin 1 of the
8473 and pin 6 of the floppy connector to pin 42 of the 8473.
Works great. Wish I would have thought of this trick when the
controller was new 15 years ago.
Cheers,
Chuck