mrbill2084
Well-known member
I was working on a pacman with a jr pac pcb in it. I think it has a bad z80a. I will swap some z80a's and see what happens. I have some parts galaga and tron pcbs I can probably find one on..
Here is what they are doing.
board 1: It almost works. It will boot up. you can see the player 1 player 2 and high score, but thats all. In free play if you hit 1 player start, the whole screen will appear, but it locks up and never starts..
I happen to have another Jr pac pcb for pac that was doa. All you see is random characters on the screen on board 2.
So I swapped every chip between the 2 pcbs and no change. But when I swapped the z80a's, the problems moved to the other board. Board 1 now has the random characters. Board 2 now shows just the player 1, player 2 and high scores.. The only difference is that hitting the start button does not make the full screen appear and lock up.
Is it possible to have a partially working z80a?
Here is what they are doing.
board 1: It almost works. It will boot up. you can see the player 1 player 2 and high score, but thats all. In free play if you hit 1 player start, the whole screen will appear, but it locks up and never starts..
I happen to have another Jr pac pcb for pac that was doa. All you see is random characters on the screen on board 2.
So I swapped every chip between the 2 pcbs and no change. But when I swapped the z80a's, the problems moved to the other board. Board 1 now has the random characters. Board 2 now shows just the player 1, player 2 and high scores.. The only difference is that hitting the start button does not make the full screen appear and lock up.
Is it possible to have a partially working z80a?
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