Re: [stella] How did they do Centipede?

Subject: Re: [stella] How did they do Centipede?
From: Manuel Polik <cybergoth@xxxxxxxx>
Date: Mon, 09 Apr 2001 08:31:58 +0200
> Dennis Debro schrieb:

> I saw an interesting question on the Atari2600 Nexus site.  How did
> they do Centipede with 128 bytes of RAM?  They kept track of where the
> mushrooms were, the score, level, number or lives, etc.  I'm a novice
> at programming Stella but it doesn't seem possible.  Could someone
> shed some light on this?

They seem to use PF1 & PF2 only. If I counted that right, it's 18 lines,
so they use 4*18=72 Bytes for tose blocks. That leaves 56 Bytes for all
the other stuff. Take some bytes for score, level & lives & some diverse
counters, they could still store some 20 sets of X/Y coordinates.

They're cheating on some things here, for example they're not buffering
how often all the blocks have been hit, they're only tracking the
current block you shoot at.


Archives (includes files) at
Unsub & more at

Current Thread