Centipede Arcade (5200) XEX File <Trakball Support> By Atlantis Games Group

[Marius]

Well...

 

in $00DA is stored lives player 1

in $00DB is stored lives player 2

 

$80B9 DEC $DA

and

$80C1 DEC $DB

 

Those two lines do decrease lives.

I have to see why these instructions are executed when START is pressed. I think START should re-init the game.

 

I am under the impression that sometimes the game setting HARD / EASY is reset by pressing START too, but I'm not sure yet.

[Marius]

Now I understand,

 

It's really a design flaw in the code.

 

Of course when the game starts you have 3 lives, and as soon as you start the lives are decreased by one. This is normal behavior.

 

It would have been much better when pressing start would lead to a fixed amount of lives left of two in stead of decreasing the lives.

 

Writing a fixed value of #$02 gives the same result, and is always right after pressing start.

 

Now I have to see how and where to put that code...

[MrFish]

Yeah, I figured that had something to do with it. I'd wondered why they chose to do it like that, when the arcade doesn't itself.

[Marius]

I have not investigated the code much further yet. It's a bit of a rats nest.

 

It seems that the code (tries to) detect whether start is pressed during game or not; well that fails.

 

The problem also happens on the lives of player two.

 

Since I'm not with emulators, I'm doing this with Turbo Freezer 2011, so it is a bit more complicated to see exactly what when happens.