Re: [stella] Gunfight 2600: Worst Nightmare...

Subject: Re: [stella] Gunfight 2600: Worst Nightmare...
From: Thomas Jentzsch <tjentzsch@xxxxxx>
Date: Wed, 21 Feb 2001 18:14:13 +0100
At 21.02.2001, 16:11, Manuel Polik wrote:
> Hi there!

> Just to show you, that I'm at least working on something, here's an
> update on Gunfight 2600.

I had a closer look at this version and had some
problems with the tabs you're using. I had to correct
the spaces myself. Could you post your settings or, even
better, could you convert all tabs into spaces with the
tabulator options of TextPad, please?

And it would be very helpful too, if you provide some
cycle counting in your kernel.

> The kernel is now pushed to it's very limits, that means:

> - Two cycles left in the kernel
> - One cycle left in the each skipdraw branch

There's another free cycles if you avoid crossing a
page at bne NextLine.

I don't understand what you're doing with gunShift at
the moment. Is it just dummy code now?

> Ok, I didn't play all my jokers yet and maybe I'm able to get rid of one
> or another CLC, SEC - or what I'm most positive about - the two EORs.

Maybe (I'm not sure) I have another joker for you:

instead of:
  SBC verPosMx

you could try:
  eor verPosMx

This would save you 4 more cycles

> Comment if you like, any ideas to squeeze another cycle out of the
> kernel appreciated.

At the moment you have a kernel where you are doing 4
color writes and dis/enabling the ball and both
missiles plus a HMOVE every line. And you're updating
the graphics and putting new values into both missile
moving registers every other line.

The most time goes into the display of the missiles.
I'm not sure, if this balance of used cycles is good.
This would be not a problem for a demo, but it could be
for a game.

I think, there is a danger, that your kernel gets to
complex. Even a very nice and sophisticated kernel
won't help much, if your game lacks gameplay.
At the moment I'm missing things where the cowboys can
take cover (like the big cactus in Outlaw). And I also
don't see how you'll be able to let the guns point at
different angles. There just isn't enough time left,
you already pushed the 2600 very nearly to it's limits.

Please don't misunderstand me, you're doing a great
job! Just think about what your game should be.

Have fun!
Thomas Jentzsch         | *** Every bit is sacred ! ***
tjentzsch at web dot de |

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