Re: [stella] Grid demo

Subject: Re: [stella] Grid demo
From: John Saeger <john@xxxxxxxxxxx>
Date: Thu, 29 Oct 1998 12:47:25 -0800

Erik Mooney wrote:
> >I didn't say this exactly right, but look at the screen. The lines that
> >have RESPx to both sets of sprites shows three sprites in the first
> >group and two sprites in the second group.  You get three in the first
> >group because the prior line only had one RESPx.  The lines that have a
> >single RESPx only show two out of the three sprites because the prior
> >line had two RESPx.
> When you say "the prior line only had one RESPx", where exactly is the
> position of that RESP0?  If that RESP0 is at position, say, 40... then on
> the next line you hit RESP0 again at 40, you will get a sprite at position
> 40, but it was caused by the *first* line's RESP0, not the second.  Because
> 40 is the current position of the sprite, it starts displaying at position
> 40, because the RESP0 for line 2 hasn't happened yet - as far as the TIA is
> concerned, it's simply a standard sprite positioning and display.

You know, this has always been a very confusing point to me.  The idea
that you do your RESPx to set up for the next line.  If it's true, it
means that when you're doing multiple RESPx on a line, then somehow, TIA
is buffering them, remembering them all for the next line.  I don't know
about that...  I tend to think about TIA as if it's rendering in real
time, reacting to RESPx pretty much right away.  But I'm probably
wrong... ;-)


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