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Coke wins could be hacked...?


anny84

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Is there a way to hack "Coke wins" in order to change game play length? This game is a bit more playable than the original Space Invaders (the score digits are also fancier) but 3 minutes are too few for a good game play. Maybe some good programmer could also think about adding time if the player completes a wave and removing time if he lose a life.

 

Good job!

Annarella Carano (Anny)

Edited by anny84
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Is there a way to hack "Coke wins" in order to change game play length? This game is a bit more playable than the original Space Invaders (the score digits are also fancier) but 3 minutes are too few for a good game play. Maybe some good programmer could also think about adding time if the player completes a wave and removing time if he lose a life.

 

Good job!

Annarella Carano (Anny)

 

like your ideas, this is one of my favorite of all space invader type games.

 

Rick

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Is there a way to hack "Coke wins" in order to change game play length? This game is a bit more playable than the original Space Invaders (the score digits are also fancier) but 3 minutes are too few for a good game play. Maybe some good programmer could also think about adding time if the player completes a wave and removing time if he lose a life.

 

Good job!

Annarella Carano (Anny)

 

Sure it is doable! I will look in to this.

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Coke Wins (Pepsi Invaders) uses 3 timers. $A7 which counts the number of frames in a second (jiffy timer), $A8 that holds the number of seconds, and $A9 that holds the minutes.

 

The subroutine that deals with the timer is here:

LF88B:
   lda	$9F					;3
   and	#$10				   ;2
   beq	LF8BA				  ;2 branch if game over
   sed						   ;2 decimal mode
   lda	$A7					;3
   sec						   ;2
   sbc	#$01				   ;2 reduce jiffy timer
   sta	$A7					;3
   bne	LF8BA				  ;2 branch if anything left
   lda	#$60				   ;2 reset jiffy timer
   sta	$A7					;3
   lda	$A8					;3
   sec						   ;2
   sbc	#$01				   ;2 subtract 1 second
   sta	$A8					;3
   bpl	LF8BA				  ;2 branch if no rollover
   lda	$A9					;3
   beq	LF8B7				  ;2 branch if no minutes left
   sec						   ;2
   sbc	#$01				   ;2 subtract 1 minute
   sta	$A9					;3
   lda	#$59				   ;2 ...and reset seconds
   sta	$A8					;3
   cld						   ;2 clear decimal mode
   rts						   ;6

 

 

...and the subroutine that resets the timer to 3 minutes is here:

;reset game timer...
LFBF3:
   lda	#$60				   ;2 reset jiffy timer (60hz)
   sta	$A7					;3
   lda	#$00				   ;2 zero seconds
   sta	$A8					;3
   lda	#$03				   ;2 three minutes
   sta	$A9					;3
   rts						   ;6

 

No provision is present to display a minute timer greater than a single digit, so you should only use a maximum game time reset value of 9:59 (by hacking addresses $FBF8 and $FBFC with new BCD values for seconds and minutes respectively). You can edit the jiffy timer to make the clock go faster or slower by editing the reset values for it at $FBF4 and $F89C...and you could have the minute timer to hold 100 seconds instead of 60 by editing the reset values for it to be $99 at $FBF8 and $F8B2.

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Another thing that bugs me about timed games is that the timer is adjusted when the player in unable to do anything...which happens in this game while the player base is flashing (start of a level/life). It's easily corrected by adding additional code at the top of timer adjust subroutine LF88B...

	   lda	$AA					;3 check if base is flashing
   lsr						   ;2
   bcs	LF8BA				  ;2 branch if so (skip timer adjust)

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...and here's the other suggestions - losing a reserve minute when hit and gaining a reserve minute when all invaders shot.

 

Sweet!! Can't wait to add this to my Cuttle Cart 2 and try this out.

 

This runs like a regular Coke Wins game, but in case I don't have that (not sure) what is the run addresses and so forth to get this to load on a Cuttle Cart?

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All these ideas are great ones, and I've often felt that three minutes was just too short to really have fun with the game. So these new hacks are excellent, and the idea of a "reward/penalty" system is creative for the game as well.

 

I wonder how difficult it would be, though, to combine all these in the same cart through selectable modes like the original Space Invaders? For example:

 

The first few modes could be "stock" games: 3 lives, 5 lives, 1 life.

The next few modes are "timed" games: 3 min., 5 min., 7 min.

And the last few modes are the same amount of time, except with the reward/penalty system in play or some variation of it.

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...and here's the other suggestions - losing a reserve minute when hit and gaining a reserve minute when all invaders shot.

 

This is great.

But when your time is under one minute, losing a life doesn't remove the remaining time and doesn't end the game. Is it normal?

 

Anny

Edited by anny84
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Yay! now the game is not timmed at all, you start with 3 lives, and when you clear the screen, you get another. If a missle hits you, you lose a live. Now the score needs to be hacked, it does not go very high.

 

Did you restore the original score points?

That's great - You can also restore the original UFO sprites, then (just a tip ;) )

 

Anny

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But when your time is under one minute, losing a life doesn't remove the remaining time and doesn't end the game. Is it normal?

 

It was. It only takes 3 bytes to fix...

 

;negative timer adjust here
   lda	$A9					;3
   and	#$0F				   ;2
   beq	LF330				  ;2 branch if already at 0 minutes
   dec	$A9					;5 subtract 1 minute
;added...
   .byte $2C					 ;4 skip 2 bytes
LF330:
   sta	$A8					;3 zero out seconds

CokeWins_add__l_time_.zip

Edited by Nukey Shay
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Yay! now the game is not timmed at all, you start with 3 lives, and when you clear the screen, you get another. If a missle hits you, you lose a live. Now the score needs to be hacked, it does not go very high.

 

Careful...there is no penalty for just hanging around to do "UFO hunting", since the invaders do not ever reach Earth in Coke Wins. So you can rack up some huge scores if you are good at dodging missiles (if you keep 4 invaders in both of the edge columns, you don't even need to do that).

 

One of the now-unused timers could be used as a UFO counter...so that only a limited number of them appear in any wave.

Edited by Nukey Shay
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New tips for new versions:

 

- Adding 25 bonus seconds for each mother ship hit.

- Restoring original sprites eventually making them smaller size (should make game harder)

- New score: 1 to 6 points for Ufos and 10 points for mother ship.

 

Anny

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All these ideas are great ones, and I've often felt that three minutes was just too short to really have fun with the game. So these new hacks are excellent, and the idea of a "reward/penalty" system is creative for the game as well.

 

I wonder how difficult it would be, though, to combine all these in the same cart through selectable modes like the original Space Invaders? For example:

 

The first few modes could be "stock" games: 3 lives, 5 lives, 1 life.

The next few modes are "timed" games: 3 min., 5 min., 7 min.

And the last few modes are the same amount of time, except with the reward/penalty system in play or some variation of it.

 

Not too difficult to work into the original game...I'd imagine. SI has 112 game variations (16 variations for each play mode)...so adding an additional 16 brings the total to an even 128 that the existing counter can keep track of. Player 2's score could be used as the timer.

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