CompuServe Messages

Many thanks for you suggestions. I've had another look at the code I wrote to check that my MOVE instructions had valid addresses, and noticed that unfortunately it only checked the destination addresses, and not very carefully either. I've spent the day re-writing this code and have come to realise that it can be an enormous help to catch invalid _reads_ as well as writes. I have since detected two bugs, one of which may well have been the cause of my problems. (I haven't managed to fix it yet.) As for an MMU, I still can't decide whether or not to invest in one. My error checking code, when it is activated, slows down processing by a factor of 50, and a hardware solution (if a really good one exists) would therefore be much more practical. I've found a copy of Mungwall, version 37.51 and the docs make no mention of an MMU, so I guess I'd better try it out. Regards, Shraddhan (via AP from Hertfordshire, England)