Hi Matt!
Do you have the Phillips Application Notes and Developement Tools for 80C51 Microcontrollers from Philips?
I think I saw some information there for interfacing the ISA with a 83xxx
controller.
The App. Notes book is comming along with the 80C51-based 8-bit Microcontrollers (describes the arcitechture, cross reference, family derivates an so on).


Best regards John E.