RE: [stella] RE: Illegal opcodes...another question

Subject: RE: [stella] RE: Illegal opcodes...another question
From: "Dennis Debro" <ddebro@xxxxxxxxxxxxx>
Date: Tue, 14 Jan 2003 09:08:54 -0500
Thanks again Thomas,
> > You're not updating y for each scanline, right?
> Right, only every 2nd scanline (-> 2LK). All objects have a two line
> vertical resolution. The positioning is done with single line
precision by
> using VDELPx (for the cars) and different kernels (for the zombies).

I had been thinking 1LK. Now I see why it's done that way.

BTW, how does VDELPx work? From what I understood from the manual it
doesn't give you players with the resolution of a 1LK but you can move
them 1 scanline at a time. Is that right?

I originally thought it would let you load the graphics registers and
just not display them until the next scanline. I quickly found out that
wasn't true unless I did something wrong.

If VDELPx could give me single line graphic resolution it would really
save me some headaches with kernel timing. That way I wouldn't be
restricted to HBLANK for loading player graphics and colors.

The 6-digit display is a 1LK, right? Is that only possible because they
are loading GRPx twice during a scanline?
Take care,

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