RE: [stella] Instruction timing tip

Subject: RE: [stella] Instruction timing tip
From: "Lee Fastenau" <stella@xxxxxxxxxxxxxxx>
Date: Sat, 9 Oct 2004 00:11:38 -0500
> > I commend your effort in trying to come up with a
> > general formula.  I don't know though...I think the
> > exceptions make it almost as hard as just memorizing
> > the chart though, IMHO. :)
>
> Right; I tried this approach before, when I split the instructions into
> various categories, and provided cycle counts for all of the addressing
> modes.  I probably should have included tables that would make it more
> useful as a cheat sheet, at least.
>
> But, really, there's no substitute for experience here.  As you program
> 6502 and apply cycle counting, you'll start to get a feel for it.
> Especially if you're programming the 2600.  It's just like how BASIC
> programmers used to have to look up all those PEEK and POKE addresses,
> but had them all memorized after a while.

FWIW, here's the cheat sheet I built and live by:
http://www.ioyu.com/io/atari/images/cyclechart.gif

And the original in MS Excel version if anyone's interested:
http://www.ioyu.com/io/atari/images/Cycles-6502.xls

I don't remember what sources I used to build it, but I just needed a
compact view without a lot of extra information.  Apologies if anything is
incorrect.

-Lee



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