Re: 6502 trashing memory cycles...

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

On 7 mar, 09:53, "Alex Freed" <a...@mirrow.com> wrote:
>
> I think one thing is missing here. On some instructions some cycles
> may be needed sometimes and not needed at other times. It should
> still work but not tag ALL of the "borrowable" cycles.
>
> -Alex.

In the case of conditional branches, I don't see how to predict if
it's going to be taken as the processor flags are unknown from the
outside. In the case of page crossings, it's also difficult if at all
possible to predict.
What other cases do you see ?

Every two cycle opcode gives you one free cycle, and every RTS gives
you 3, and pushes and pulls gives you 2. There are a lot of instances
of these in any program... lots of memory cycles that could be used
for... what ? hehehe

Regards,
Jorge.