Dan, I don't think I've ever seen a 5.25"
PCMCIA drive. Do they exist? There's actually not a huge amount of difference
between the PCMCIA bus and ISA. IIRC, you can get PCMCIA-PC104 adapters and PC104 is very
close to ISA.
Cheers,
Chuck
These guys made one ten years ago, there might be some around.
http://www.accurite.com/PR-PC.html
Dan