I've taken it upon on myself to provide a schematic answering the question,

"How do I attach an 8255 to an 805x?"

for cases in which the external memory bus already exists:

for those which have no external memory bus:


Surely these have appeared here and there in the past, in one version or another, but just for the record ... here they are.

A little more info is included on my user page.

RE