Re: A jewel...

["bieling@terra.es" <bieling@terra.es>]

On Feb 26, 5:39 am, Jerry <SNIPawande...@yahoSNIPo.ca> wrote:
> biel...@terra.es wrote:
> > <http://www.wiz-worx.com/resume/byte8010.htm>
>
> Neat idea.
>
> In practise I think SWEET-16 was faster, since BRK-IRQ processing takes a
> bunch of time for each instruction.  Not to mention this hardware mod isn't
> going to be on very many machines out there.  For more variety than
> SWEET-16 offered, one could write a different virtual machine language.
> P-code comes to mind as another Apple II example.
>
> --
> --  Jerry  

I find this hack cool, only that I don't see a reason to trash even
more cycles in every round trip by saving/restoring all the registers.
If it is about adding opcodes, none of the existing ones save/restore
them. Even more, the S register, the most important one for flow
control, shouldn't probably be restored at all if the new opcodes were
to be useful... isn't it ?

Also, I'm not sure how much room has been left for new opcodes by the
65c02. Even though a single second NOP opcode would suffice to make it
work. Hey, with this hack probably a 65c02 could be almost fully
synthesized from a plain 6502.. (although the 65c02 specific opcodes
would run much slower).

Jorge.