Great Exploitations

This looks very good - the colouring on the enemy cars works well, and they are clearly distinguished from the player. How about placing an arrow at the top or bottom of the screen (ET style) to indicate the location of the nearest flag, rather than using a radar?

 

Chris

This isn't strictly applicable to a bB port, but I was thinking that a good way to get three enemy cars all differently colored from the player's car would be to use P1 for enemy cars, same method as now, and use P0 for your car and an enemy car, but change P0 color midscreen: if the enemy car is above the player car, set COLUP0 before the kernel begins and reset COLUP0 either immediately after drawing the enemy car or immediately before the player car, do the opposite if the enemy car is below the player car. If the enemy car and the player car overlap, then flicker the three enemy cars with P1.

 

I think this would look pretty good, as it would only flicker if all three enemy cars overlapped (vertically) with the player's car, which probably would happen pretty rarely. Of course, you can't do this in bB (yet?), but maybe it could be done with small modifications to the bB kernel? It would only require a single color change per screen.

 

I can't remember how much spare time there is in the standard bB kernel, but it could be done like...

   cpy ColorChangeLine
  bne NoColorChange
  lda NewColor
  sta COLUP0
ReturnToKernel

;--outside the kernel:
NoColorChange
  nop
  jmp ReturnToKernel

11 cycles. With some tricks, maybe could be done in fewer. Just a thought.

 

EDIT: Okay, now I actually looked at your binary.

 

Looks really good, the cars are easily distinguishable from each other. I also like your flag (the ball, I'm assuming).

 

And, depending on RAM, you could probably have more than 3 enemy cars; just have to devise a movement algorithm that keeps <= 3 on the screen at any one time.

I think for a really close port you'll need some sort of intelligent flicker for the enemy cars. I think the Arcade adds one additional car each level. If you play to the bonus round (level 3?) there's lots of cars sitting there, on top and bottom, that might be the maximum. Might be less cars in "New Rally-X", at least it starts easier.

I think for a really close port you'll need some sort of intelligent flicker for the enemy cars. I think the Arcade adds one additional car each level. If you play to the bonus round (level 3?) there's lots of cars sitting there, on top and bottom, that might be the maximum. Might be less cars in "New Rally-X", at least it starts easier.

 

I agree intelligent flicker would be better, but that's clearly getting outside the realm of bB. Even tracking very many cars would be pushing the limits of variable storage. Still, it might be interesting to have more than three cars and having logic so that the extra cars would hang around near the edge of the player area.

This is only kind of related - but it occurred to me that a possible future kernel for bB might be one with *no* playfield!

 

But instead, uses all that RAM to store sprite data and has a big, 5-10 sprite flicker engine. 1 sprite non-flickered and 8-10 intelli-flickered. Plus missiles. Kinda like Manuel's Colony 7 kernel.

 

The lack of playfield would hurt a little, but having that many sprites might make up for it.

This is only kind of related - but it occurred to me that a possible future kernel for bB might be one with *no* playfield!

 

But instead, uses all that RAM to store sprite data and has a big, 5-10 sprite flicker engine.  1 sprite non-flickered and 8-10 intelli-flickered.  Plus missiles.  Kinda like Manuel's Colony 7 kernel.

 

The lack of playfield would hurt a little, but having that many sprites might make up for it.

Sure, a playfield-less kernel would be useful for some games. Lots of games use no playfield. Not sure when I'd have time to write a new kernel though... Maybe summertime.

 

As for adding extra cars, that might be possible eventually, as currently, around 15 bytes of RAM is free (though these can easily get used up by other things.) For now I will add more gameplay elements and see how things go. Maybe I can ramp up the difficulty without adding cars, like make them smarter. In the original game, the cars just give chase, and in higher levels they go faster, necessitating the smokescreen. Maybe in later levels I can make one enemy try to flank the player car.

 

Come to think of it, I am not sure quite how to implement the smokescreen. Maybe add a playfield block but flicker it at 30 Hz?