Is there a FAQ on installing IDE HDs somewhere?
Perhaps we should write one!
edit: on a more helpful note...you can mount a 2.5" IDE (laptop) HD in an A1200 (this is how the A1200HD originally shipped), or I think with a bit of work a 3.5" IDE HD. Where you can get the cable I don't know...I'm sure someone here will run you through the formatting/installing procedure. BTW do you have the original Workbench 3.0 disks?