Z-80 code question about a loop that depends on the contents of the refresh register

Ethan Dicks ethan.dicks at gmail.com
Tue Dec 13 16:51:54 CST 2016


On Tue, Dec 13, 2016 at 5:49 PM, Ethan Dicks <ethan.dicks at gmail.com> wrote:
> I'm disassembling a vintage program...
>
> MYSUB:
>   LD A,R...
>
> So far, this loop hangs on all three emulators I've tried - simh's
> altairz80, simcpm010 for AmigaDOS, and EMUZ80 for Raspberry Pi.  I'm
> guessing none of these environments emulate specific behavior of the
> Refresh register?

I found this, BTW, which explains some of how the R register works...

http://www.worldofspectrum.org/faq/reference/z80reference.htm#RRegister

-ethan


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