> >Another stupid question, can anybody tell me precisely what the effect
> >on the memory mapping is when you turn on the 'enable diagnostic ROM' bit
> >on PB7.
> >I've just discovered (after about 1 1/2 years!) that if you type 'BYE' on
> >my modified 800 the system crashes :(. The ROM image looks OK, so I
> >think the decode logic must be confused.
> How is your 800 modified?
Heavily 8-) -- It's switchable between 800 w/256K Axlon lookalike, 130XE
and 320XE. I've got both OS ROMS and BASIC in one EEPROM (27C512), and
a big PLD to switch everything around. Oh, and there is an extra PIA that
gets switched in in place of joysticks 3 and 4 when you turn on the XL/XE
OS. It still doesn't have a PBI though - maybe I should work on that...
I was just about to start writing it all up for the amusment of the 8bit
community, and discovered this little problem, which I'd like to resolve
before I release the mod docs.