I have been quite busy lately so I have not had as much time to spend on my projects as I have wanted to; however, I have had some time to do some more debugging of the 4 Bit computer.
I have written a couple of very simple programs just for testing purposes but none them seem to work for very long... once I get more time I will do some proper debugging. They seem to work fine for a couple of computer cycles before they go into randomness.