Re: [stella] entropy & randomness

Subject: Re: [stella] entropy & randomness
From: "R. Thavas" <urchlay@xxxxxxxxxxxxx>
Date: Wed, 10 Oct 2001 18:25:41 -0400 (EDT)

On Wed, 10 Oct 2001, Chris Wilkson wrote:

> On Wed, 10 Oct 2001 urchlay@xxxxxxxxxxxxxxxx wrote:
> > Is there anything actually random in Pitfall? The game seems the same
> > every time... Pitfall II had what, some sorta hardware random number
> > generator? I've got the disassembly of River Raid that was posted here,
> > will look when I get home.
> Exactly!!!  The whole point of those LFSRs is that they are only quasi-random.
> The Pitfall LFSR is sequential not only forwards, but backwards as well.
> This enabled David Crane to fit a *huge* map (255 rooms, IIRC) that is always
> the same, into just a few bytes.  It's such a beautiful thing.
> -Chris

When I was a kid, I always thought pitfall would have been more challenging if
the map really had been random, different each time you play. I suppose it
would have been impossible to compare your score to your friend's, but otherwise
it would have been great.


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