Then about 6 hours trying to figure out an intermittent problem that has now become permanent:
- Stepping through program slowly / by hand register contents are random
- Sometimes works at full speed
- Sometimes randomly jumps out of program
- Is interupt /NMI getting generated? I've not noticed any IORQ + M1s - these lines should be pulled high
- Is ROM corrupted - had trouble then it worked then trouble so doubt its the ROM
- More decoupling!
- Buffer memory data bus?