Date   : Fri, 13 Mar 1998 20:10:42 +0000 (GMT)
From   : Rich <rst20@...>
Subject: Re: [BeebEmul8] Master OS

> On Fri, 13 Mar 1998, Mark Usher wrote:
> 
> > Can anyone tell me to which memory address the Master OS is mapped ?
> > ie the BBC is &C000 to &FFFF (or &8000 to &BFFF depending on Jumper 21)

Yeah, that's right, MOS 3.20 lived between &C000-&FFFF, with some other
routines in the Terminal Rom (Rom 15) - and the two are very closely
linked.  I haven't a clue if there was anything vital in any of the other
roms!

Also I seem to remember that most of the time, the bit of OS between &C000
and &DFFF was usually mapped out and replaced by 8k of RAM.  To get at it
(I think it contained all the graphics routines) you had to do some weird
fiddling with the paging register at &FE34, though I can't remember which
bit controlled it for the life of me.

Cheers,
Rich