John:
I have some information about the IDE interface that I find some time ago....If my memory don't fail, It's basically use an 82C55 and a 74LS04 to connect directly to the Hard Disk over an 8 bits data bus.
Also, in the document are a description of the signals pins (In & Out).
If you are interested on it, I could search that info in house and sent to you... or everybody...

Best regards.

Omar Martinez