Steve, as always I appreciate comments. Perhaps you can "babysit" me a little more..
(please remember the book Ive got is USELESS, but I am trying...)

MOV P2, #0000
If we assume this is the first line of your code, then this HAS to be JMP Start
I caught this shortly after posting.

INT5: Where IS this interrupt vector ????
Whats an interupt vector? :-)

Make sure the int5 flag is CLEAR here before you enable it.
MOV 0E8h, #11101000b ; Extended Interupt Enable (Should enable INT5)

What does this "flag" do? I was under the impression 0E8h is the only thing I would need to change for it to work.