Solder
Member
Been working on a Centipede board for a few hours and can't seem to isolate a really obscure fault, as follows:
Game plays okay and attract mode works, but on power up/game start TWO centipedes appear - one starts at the top of the display as it should, BUT it's red in colour instead of green and has no legs.
A couple of inches below it is another centipede but this one is white, and HAS legs!
The white centipede exactly copies the movements of the red one (ie the 'real' one) but the white one kind of 'exits' the screen about half way down.
About a quarter of the way down the screen the red one then becomes the green one WITH legs at the same time as the white one vanishes.
Also on startup a white flea appears in a semi random position roughly in the high scores area.
Everything else is okay.
Thought it may be a fault with the horizontal motion object circuit but can't find anything wrong, and poking around everywhere else hasn't helped either.
RAMs and ROMs are fine.
Any ideas please?
Game plays okay and attract mode works, but on power up/game start TWO centipedes appear - one starts at the top of the display as it should, BUT it's red in colour instead of green and has no legs.
A couple of inches below it is another centipede but this one is white, and HAS legs!
The white centipede exactly copies the movements of the red one (ie the 'real' one) but the white one kind of 'exits' the screen about half way down.
About a quarter of the way down the screen the red one then becomes the green one WITH legs at the same time as the white one vanishes.
Also on startup a white flea appears in a semi random position roughly in the high scores area.
Everything else is okay.
Thought it may be a fault with the horizontal motion object circuit but can't find anything wrong, and poking around everywhere else hasn't helped either.
RAMs and ROMs are fine.
Any ideas please?
