RE: [stella] Generic kernal or just build a game?

Subject: RE: [stella] Generic kernal or just build a game?
From: stella@xxxxxxxxxxxxxxx
Date: Sun, 14 Mar 2004 21:34:24 -0600
Yeah, I figured 99% (if not 100%) of all Stella games have their own
kernals, even if just modified versions of their predecessors'.  As you
stated, it would just be nice to attempt a generic kernal for the sake of
experience.  I think my requirements were just a bit too ambitious though.
The definition of each "object" (sorry for the OOP speak) included
properties like X, Y, delta X, delta Y, color, and naturally a shape
pointer.  HA!

Needless to say, I was getting discouraged -- hence my post.  I do want to
continue building a generic kernal though.  I'm going to cull the
requirements down to... say... "Atari 2600 Pac-Man" levels.  Well, maybe not
that barebones, but one shape, one color, multiple copies, and probably
"dumb" flickering to start with.  The major sticking point will likely be
that pesky horizontal positioning.  I'll be referring frequently to this
excellent document, I'm sure:

I might concurrently work on a game idea that would translate well to
Stella.  I don't remember the name, but it was on a Compute! Gazette
diskette (I think) for the Commodore 64.  The concept was basically Breakout
in the round, where the center of the screen contained a solid rectangle of
blocks and the player had two paddles that rotated around the center
opposite each other, as illustrated in figure 1.

 X     .
      XXXXXXXX    X

       fig. 1

Technically, this could all be built using playfield graphics and a ball (or
missile (or player)).  I don't think I'd need to use any special tricks,
except to create the non-mirrored playfield.  Also some timing
considerations for getting the paddles to be a different color than the
blocks.  Anyway, I'm sure as simple as this seems to me right now, I'll
probably hit some technical (or mental) roadblock that will make me hang up
my Atari paddles for good. :)


Thanks for your response!

-----Original Message-----
From: owner-stella@xxxxxxxxxxx [mailto:owner-stella@xxxxxxxxxxx]On
Behalf Of Eric Ball
Sent: Sunday, March 14, 2004 7:49 PM
To: stella@xxxxxxxxxxx
Subject: Re: [stella] Generic kernal or just build a game?

> Anyway, my question is:  Is it worthwhile to build a generic kernal or
> should I dive right into game-specific kernal development?

I believe that most 2600 games use a kernel designed specifically for the
game.  Each game has a different set of requirements, thus needing a unique

This isn't to say that a hypothetical semi-generic kernel wouldn't have some
value.  (prototyping maybe?)  If nothing else, doing one will provide you
with significant experience and techniques and routines which you can reuse
in the future.

Thought - a "generic" 2600 kernel would probably have similar capabilites as
the 5200 in low-res mode. :-)

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