Date   : Tue, 05 Mar 1996 11:28:52 GMT
From   : lamcw <lamcw@...>
Subject: Re: BBC: Radical rethinks! :-)

Robert Schmidt wrote:

;>Okay, I thought, what now. I've lost the whole thing (all the code, my 
;>copies of the ROMs, the whole lot...) but it's a project I don't want to 
;>give up on. So, I thought, I'll write another one.

;That's the spirit!

Atta boy!


;>Introducing... TOL. I think I'll keep the suspense about what it stands 
;>for going for a while.

;Well, your web page spoils the suspense!  :-)   By the way, your page says
;that it is illegal to use copies of the Acorn ROMs.  This is only true if
;you don't own a BBC, right?


I believe it may be, just may be, illegal to use the ROM out of the
context it was intended for, i.e. inside a real Beeb. Can someone clarify?


;>tad boring. Thirdly, I don't really know C very well and I think a major 
;>project like this would help a lot.

;I agree that C is the way to go.  If I was to write an emulator from scratch
;(which I am seriously considering), I would even consider using C++, but I
;realise that the overheads of C++ will be significant, even though they are
;small.  (For example, I like the idea of having a 6502 class, but all that
;passing of the "this" pointer around might be enough to kill its usability.)

For speed, I strongly advise against the use of any user-defined functions.
The overheads are high. Don't design your opcodes as functions.

GOTOs are a very good idea :)


;One thing I'd consider implementing in an emulator is more OS hooks -

Can't really recommend this... fewer OS hooks means higher compatibility
which is achieved by emulating the paged I/O memory as well as possible.


Chris Lam.
MacBeebEm Keeper.