Re: [stella] Double line resolution

Subject: Re: [stella] Double line resolution
From: "Eric Ball" <ericball@xxxxxxxxxxxx>
Date: Wed, 28 Jan 2004 21:50:03 -0500
From: "David Davies"
> I'm just trying to understand the use of double-scanline resolution. Does
> the TIA keep all its register values for each scanline until you change
> them? Where sprites are concerned, do you need to use HMOVE after every
> WSYNC, or do you only do it every 2 WSYNCs in the case of double-scanline
> resolution?

I think you are thinking of a 2 line kernel (2LK) where the GRPn registers
are only updated every other scanline.  (VDEL confusion notwithstanding.)

HMOVE is used to reposition the sprite, so unless your sprite is shifted top
to bottom, you will typically not do an HMOVE (or at least a non-zero HMOVE)
while displaying a sprite.

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