Re: [stella] Pitfall! LFSR

Subject: Re: [stella] Pitfall! LFSR
From: Glenn Saunders <cybpunks2@xxxxxxxxxxxxx>
Date: Mon, 10 Sep 2001 02:04:26 -0700
At 10:41 AM 9/10/2001 +0200, you wrote:
As I'm just finishing the Pitfall! disassembling, I would like to know, if David has a name for that special LFSR.

LFSR is a modern term for it, but in the Atari days they called all this stuff, whether in software or hardware (like the 2600's horizontal motion and audio circuitry), polynomial counters.

He called it an 8-bit polynomial counter and he said he experimented with various seeds in order to make sure the game it produced was interesting.

I actually have a flash file I made that shows how a polynomial counter routine works...

Larry Kaplan said that polynomial counters were an outgrowth of a magazine article that came out in the mid 70s on the subject, I think it was in Byte magazine or something, and after that everyone started using them.

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