> Tricky problems with 2600 emulation ...... volumes 1 to 73 :) Much easier
> now the hardware is faster though.
You are under the mistaken assumption that I have fast hardware :)
In actual fact, I have 16.78MHz.
Cheers
A
-
Andrew Davie, TwoHeaded Software
adavie@xxxxxxxxxxx
----- Original Message -----
From: <AutismUK@xxxxxxx>
To: <stella@xxxxxxxxxxx>
Sent: Saturday, November 03, 2001 12:28 AM
Subject: Re: [stella] 6502 hardware register writes
> In a message dated 02/11/01 8:57:28 GMT Standard Time,
adavie@xxxxxxxxxxxxx
> writes:
>
> << Being somewhat interested in working on a '2600 emulator, I thought I'd
> start by asking if writes to hardware (ie: graphics) registers occur on
the
> last cycle of the instruction. That is, in, say, a 3-cycle store, does
the
> effect of writing to the register become visible on the first pixel
> immediately drawn after the end of the 3rd cycle? Or is it apparent at
the
> start of the 3rd cycle (ie: end of 2nd cycle)?
> In general, I'm interested in discussing '2600 emulation - perhaps those
on
> the list who have tackled this, and can help when tricky problems show
up,
> might hold up their hands. >>
>
> I think they occur on the last cycle, but it probably doesn't matter
because
> almost all the syncing is done by sta (something) anyway. It could be
> problematical if for some reason you wanted to use inc or dec to do a
> write.
>
> Tricky problems with 2600 emulation ...... volumes 1 to 73 :) Much easier
> now the hardware is faster though.
>
>
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