Re: 6502 Simulator

["Shawn B." <leabre@html.com>]

I had thought about that, but, the process is a little more automated, plus
you can immediately save your asm file because if you make the change in hex
only, then you have to not only look up the opcodes (unless you know them by
heart), but then go and decipher them into the mnuemonic instruction later
in the asm file.  Actually, it isn't a lot of work.  I have a working model
and it is quite easy to implement.  What is not easy to implement is the
fact that I want it to be so dynamic that I can plug other CPUs and
debuggers into it and extend it that way.  I need to come with a good
interface.

Anyway, I would make the change take effect as you are typing but I'd rather
wait until the breakpoint because then it knows for certain what
instructions you are intending.

Thanks,
Shawn


"Sheldon Simms" <sheldonsimms@yahoo.com> wrote in message
pan.2004.02.17.14.55.51.376286@yahoo.com">news:pan.2004.02.17.14.55.51.376286@yahoo.com...
> On Tue, 17 Feb 2004 04:35:55 +0000, Shawn B. wrote:
>
> > Now for the reason I'm making it in the first place: when you are
debugging,
> > and a breakpiont is set, you can modify the source code and next time
you
> > step the breakpoint, it will execute your new instructions as if you
> > originally compiled it that way.
> >
> > The way I intend to implement this trick is like this:  when you chance
the
> > source, and step the breakpoint, it will then recompile the program
(only
> > your source code) and overlay the old memory with the new memory and
then
> > adjust any branches and references as necessary and then adjust the
Program
> > Counter to the necessary memory location to cause the change to "appear"
to
> > have taken effect.  This way, if I have a nasty defect that I"m trying
to
> > correct, then I can just keep it in the breakpoint and change the source
as
> > I'm debugging without having to constantly start over again.
>
> Sounds like a lot of work to me. Why not just allow the user to select
> an address in memory (preferably by clicking on it) and then just type in
> new instructions which are immediately assembled and and inserted there?
>
>