Date   : Fri, 26 Jan 1996 14:36:21 +0000 (GMT)
From   : sf4000@... (Steven Flintham)
Subject: Re: Would this work?

> Tom Seddon wrote:
> >
> >On Fri, 26 Jan 1996 jkb@... wrote:
> >> No. The OS is more than a collection of OSWRCH type calls. However
you don't
> >  ^^
> >!!!
> >
> >I have written an emulator which worked in the way he described. It worked
> >fine! However it was on the Atari ST so it was rather slow (~40-50% BBC
> 
> Ok I take it back :-)
> You _could_ trap all the OS requests, assuming you know them. My preference
> would still be to keep the OS if you can. However as the other method does
> indeed work, then you have a choice :-)
> 
> Bye for now,
> 
> 	James

As it seems that my original idea will work, I will stick with that for
now as I'm not sure I'm up to writing a full emulation which could run
the original OS. I assume I'm right in thinking that, although the OS
is far more than just the OSWRCH type calls, when running BASIC they
are more or less all I need.

Even if I do want to try and extend it to a full emulator at some later
stage, doing it the simple way first will let me test my 6502 emulation
fairly thoroughly without having to worry about bugs in the rest of the
emulation. Also, since I'm using a RISC OS machine, I can (initially)
avoid the need to write C versions of the relevant OS routines by just
calling the corresponding RISC OS SWIs.

Steven

(Just in case it makes a difference: I haven't actually received the
original post saying it wouldn't work yet, only the replies, so
apologies if this is wrong/duplicates something already said.)