Re: [stella] TomInv testing with Supercharger reveals anomaly

Subject: Re: [stella] TomInv testing with Supercharger reveals anomaly
From: "Eckhard Stolberg" <Eckhard_Stolberg@xxxxxx>
Date: Thu, 9 Aug 2001 18:48:54 +0200
> Since I have no change to test things on real hardware (I do everything
with z26), I did send some code to Eckhard.
> He told me about a problem with the positioning, and I thought I fixed it.
Maybe the bug accidently came back. Someone should test this on a 2600.

If this is still the same program that you sent me, it should work
correctly on my PAL VCS, but have problems on all emulators.

IIRC you were postioning a set of sprites near the end of the scanline
so that the next copy would just be spilled into the next scanline.
During the horizontal blank you switch that player from close spacing
to wide spacing, so that the copy in question shouldn't be displayed
anymore. But since the VCS had decided on the end of the last scanline
that the copy must be displayed, it would still do it anyway.

If the 7800 has been changed in such a way that changing the spacing
has an effect to that player copy, then the multisprite trick
with hitting RESPx multiple times might get messed up a bit and the
reported display problem might result from that.

Ciao, Eckhard Stolberg

Archives (includes files) at
Unsub & more at

Current Thread