Re: [stella] Thrust v0.9

Subject: Re: [stella] Thrust v0.9
From: Eckhard Stolberg <Eckhard_Stolberg@xxxxxxxxxxxxxxxxxxxxx>
Date: Sat, 17 Jun 2000 14:10:34 +0200
>Just listen to Thrust: when using Shield (DOWN) and
>Thrust (FIRE) together, the result is much louder than
>expected and doesn't sound right. 

I was thinking more of something small enough to run in a supercharger,
so that I could compare it to a real VCS. Anyway. I tried Thrust on z26
and when I turn the shield on and then press fire, the ship thrusts the
engines instead of firing. So the problem might actually be something
with the joystick handling routine.

When I thrust forward and fire at the same time both sound effects
happen nicely at the same time too, so I can't confirm any problems
with using both sound channels together.

>The turning speed matches the speed of the C64
>original now. I'll make it slower (are 20% reduction
>enough?) in rookie-mode.

I'd have to try it out to be able to say if 20% are enough. When I
try the game at 50 frames, the controls are already much better. But
then everything else is also slower, so I can't say if changing the
turning speed alone would make the game easy enough.

>Yes, that's a good idea. I thought about two different
>bins when i started developing Thrust. Your idea is
>much better, i think correcting the timings for VBLANK
>and overscan and some game-speed-parameters should do

That would help, although most PAL TVs can handle 60Hz displays just
fine. The real difference is in the palette. If you use the -c1 option
in z26, you can see how the game would look like on a PAL VCS. And
when you have changed the display to 312 lines per frame, the -5 option
can help you adjust the timing as it lets the game run at 50 frames.

One other thing to make sure for PAL mode is that you always do an even
number of scanlines per frame. Stella for DOS does display this number
after exiting, but unfortunately Thrust doesn't run on it because of the
undocumented instruction.

I don't have the capability to play bankswitched games on my VCS, but if
you create the binary so that bank1 is located at $9000, bank2 is at $B000,
bank 3 is at $D000 and bank4 is at $F000 and all JMP, JSR and direct memory
accesses use the apropiate addresses for this setup, then I can make your
game work on my 7800 RAM cart as a flat memory model 2600 game. That way I
could tell you how well it works in PAL on a real system.

Some late Atari games like Sentinel or Shooting Arcade use this memory
setup, since Atari used a similar system to develop these games, and I can
play those on my RAM cart with only very small changes.

>I have no idea how to contact Firebird. I thought it
>would be legaly better to put their copyright in the
>game and the manual, because both are very similar to
>Firebird's C64-version. I don't know much about the
>law, maybe you can help?

I'm no legal expert either, but I think that over here using the same name,
music, graphics, texts or level layout (if it is graphical like in a tile
based game) is a violation of copyright. In the USA there is also something
like a copyright on the "look and feel" of a game. But I think this is
pretty difficult to prove in court.

Anyway, whoever owns the copyright to Firebird and Thust now probably
doesn't care much about a violation to it through a VCS game. But
using the name Firebird in the copyright message could make some people
believe that Firebird has actually something to do with this version,
and that might be something that the Firebird owners could care about.

So I think giving the game a little more unique touch and making it
a little less like the original that way, might be a good idea.

BTW, in the game, when I loose the last life at a higher level, a new game
starts at that level again. Is that intentional?

Ciao, Eckhard Stolberg

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