wrote:

One of my old Gateway laptops (WinXP) uses an external (NOT USB
connected) FDD (could not find replacement) that is defective.

I have some good laptop FDDs, but different brand (from Thinkpad, etc.).

Is it possible for me (I was once a service tech, TVs, VCRs, etc) to
rewire the connector to use this other brand FDD?

Thank You in advance, John

You can't open the external enclosure to replace the FDD inside of it?
Else, you'd have to map the 25 pins on the parallel connector to the
wires to see which ones were used for which purpose inside the case.
Just because they used a standard port layout doesn't mean they didn't
use a proprietary wiring setup inside the case. They could've made the
FDD wireing proprietary to their driver's support, like deliberately
screwing with the data out pins as to which order the FDD used.

If the FDD uses an IDE connector, that is a 16-bit bus versus the 8-bit
for the parallel port, so the driver would have to buffer for double
reads or writes.

Probably should open the case to see what interface the FDD inside uses.
There were also 50-pin SCSI FDDs, too.