no offense take Lord Nightmare, but interesting comments. I really don't think I've had one fail, but given your input I don't think I'm eager to take one apart either!

I found (long ago) one other source which is a zipped collection:
I recommend miscin.doc which has some discussion of where
the keyboard buffer and counter are stored in memory.
And rbgibm.doc which talks about differences between ibm
and rainbow bios.

I still have not attempted to look at the code in detail, but how do you know where to locate the ROM images you guys obtain?

Regards, Will