It works! The damn thing works!!
Well, okay, there were a few bugs in the Verilog, but checking out each block soon ironed out those.
Ta daaa.... Start up screen:
A quick graph showing that scans are working (needed the external interrupt line wired up properly - took an evening to fix that little bug):
The PC that I am using is an Advantech industrial control PC in a small case. It has a 486 processor running DOS 5.00.
For now, this is just what I need. Perfick!