Re: Positioning during VSYNC (was: [stella] DD_0003)

Subject: Re: Positioning during VSYNC (was: [stella] DD_0003)
From: "Eckhard Stolberg" <Eckhard_Stolberg@xxxxxx>
Date: Wed, 26 Sep 2001 21:52:15 +0200
> John wrote:
> > Well, I think you *can* do any positioning at any time, but I'm not
> > convinced that you will get the same result on all variations of
> I'm positioning (except HMOVE) during VSYNC in Thrust and Jammed. Nobody
reported any problems with that so far.
> During development, I mostly had to rely on the nearly perfect emulation
of your z26, and it is emulating exactly in the described way. I guess, you
are doing it that way for good reason? :)

I think John was referring to the discussion we had a while back
on positioning differences on different models of the 2600 and 7800.
For example the score in games like Kool Aide Man and Thunderground
would not display properly on my PAL 7800s and on one of my PAL
2600. There was someone else who reported the same problem with one
of his NTSC 2600s.

The different positions for the score in these games probably is
due to the strage way of accessing the positioning registers.
So while you can access the positioning registers at any time,
you should be carefull with doing any too fancy stuff, or your
program might not display properly on some of the consoles out

Ciao, Eckhard Stolberg

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