As Jeff pointed out, the IDE port is an XT-IDE, not te be confused with AT-IDE we all know and love (or hate).
This port WAS used in the A590, often the standard 20MB drive that came with was of the XT-IDE flavour.
You can NOT use ANY AT-IDE stuff on it, so forget about hard drives, CF-Card readers, CD-Rom drives etc.
The only thing which will work on the port is an (ancient) XT-IDE drive, iirc no drives larger then 40MB were ever made.
