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:ftp://ftp.update.uu.se/pub/rainbow/doc/rbtecdoc.zip
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?