Re: [stella] playfield RAM usage

Subject: Re: [stella] playfield RAM usage
From: Erik Mooney <emooney@xxxxxxxxxxxxxxxx>
Date: Sun, 04 Mar 2001 18:04:57 -0500
On Sun, 04 Mar 2001 01:52:48 -0800, you wrote:

>At 04:26 AM 3/4/2001 -0500, you wrote:
>>That's what I did for INV way back when, and the playfield manipulations
>>wound up mutating and growing and engulfing the entire kernel :)   It
>>winds up taking a fair chunk of both RAM and kernel CPU, but it could work
>>pretty well here.
>What's the most efficient way to store playfield in RAM anyway?  I'm only 
>using PF1 and PF2 (hence 4 bytes per scanline) but for a full-width 
>playfield bitmap PF0 is only going to use a nibble.

For INV, I used six bytes per line, because there wasn't time in the
kernel to do any additional processing for the PF0 nibbles.  I only had
five lines of playfield, though (the animations are calculated during the
kernel), which meant it took 30 bytes of RAM, not at all excessive to hold
by far the largest chunk of game data.

FWIW, I rarely came near running out of either RAM (20+ bytes left even
after Piero's additions) or ROM (3 pages free), so it's a bit odd to me to
see ANdrew so cramped for space... But then again I never finished my game
(and won't, I can't even understand the code anymore), so who am I to
judge :)

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