the hard drive is definitely a replacement. The orginal XT harddrive was a full height and I believe it was a Seagate ST412 (10 meg). As for the floppy controller, it may have a bios extension on board in rom that contains the driver for it unless there was a XT bios upgrade available for it, but I don't recall that or IBM creating a 3.5" board for the XT best regards, Steve Thatcher I picked up an old IBM XT today and it has a 3.5" floppy drive in it (and it works!) Anybody ever heard of this? The drive has it's own controller card and both it and the drive appear to be IBM parts. )I haven't pulled everything apart to be sure.) FWIW the computer also has a FH 5 1/4" floppy drive and a HH 5 1/4" 10 Mb hard drive with a Seagate logo on the front of it. Anybody know if this is an original XT hard drive or a replacement drive? It's been so long since I've seen an original XT with the 10 Mb drive that I don't remember much about it.