Checking score for extra lives

[+mksmith]

Currently i'm trying to add additional lives once you reach a stated number (in this case first 20,000 then every 60,000 points). I'm trying to do the following:

 

 sc0=score0

 sc1=score0+1

 sc2=score0+2

 scoreLifeBenchmark = 0

validateExtraLife

 rem check 20,000

 if sc0 >= $02 && scoreLifeBenchmark = 0 then playerLives = playerLives + 1 : scoreLifeBenchmark = scoreLifeBenchmark + 1 : goto _exitValidateExtaLife

 rem check every 60,000

 value = 6*scoreLifeBenchmark

 if sc0 >= value then playerLives = playerLives + 1 : scoreLifeBenchmark = scoreLifeBenchmark + 1 : goto _exitValidateExtaLife

_exitValidateExtaLife

 return thisbank

 

So essentially what happens as you reach a benchmark it increases that value by one thus you can then check 6*1=6 (60,000), 6*2=12 (120,000), 6*3=18 (180,000) etc against the first 2 digits in the score.

 

Can anyone shed some light - the score stuff does my head in regularly!

 

 

 

Edited June 26, 2019 by mksmith

[RevEng]

You're close. The thing is, the score is stored in BCD format, and stuff like "value = 6*scoreLifeBenchmark" isn't BCD compatible - the 6502 can only add and subtract in BCD format.

 

I haven't tested it out, but something like the following should work...

 

sc0=score0
 sc1=score0+1
 sc2=score0+2
 scoreLifeBenchmark = 0

validateExtraLife
 rem check 20,000
 if sc0 >= $02 && scoreLifeBenchmark = 0 then playerLives = playerLives + 1 : dec scoreLifeBenchmark = scoreLifeBenchmark + 6 : goto _exitValidateExtaLife
 rem check every 60,000
  if sc0 >= scoreLifeBenchmark then playerLives = playerLives + 1 : dec scoreLifeBenchmark = scoreLifeBenchmark + 6 : goto _exitValidateExtaLife
_exitValidateExtaLife
 return thisbank

 

[+mksmith]

Ah yes can't multiply - did read that thinking back now ? ? ? I'll try that out shortly thank you ?

[+mksmith]

That fixed it - thanks Mike ?

[RevEng]

You're welcome. One step closer... ?