On Fri, 5 Feb 1999, Maarten ter Huurne wrote:
> The default MSX interrupt handler pushes all registers (normal and
> alternative) to the stack. This is safe, but slow.
> If you choose not to use the alternative registers in your program, and not
> to use them and IX and IY in your interrupt routine, you can make a much
> faster interrupt handler:
>
> intHandler:
> ex af,af'
> exx
> ... handle interrupt ...
> exx
> ex af,af'
> ei
> ret
I've been wondering. Except for the opcode and the timing, is there a
difference between RET and RETI? I know RETN does iff1=iff2, RET. But my
documentation on RETI only says that the program knows the interrupt is
finished. Now my programs don't know anything themselves... Is it just to
be compatible with later (or earlier) versions of the Z80, which might do
something different, or does it do something I don't know about?
Bye,
shevek
---
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