Centipede screen displays alphanumeric characters in reverse orientation

S4Patrick

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Centipede screen displays alphanumeric characters in reverse orientation

Everything works with the game fine; game play, sounds, coin-up, etc.

The odd thing is that the high scores table (both initials and score), and "credits", "bonus every 12000", and your score in the upper-left corner are all displayed backwards, as if it's being held in from of a mirror.

On the bottom of the screen display, where it says "1980 Atari", that reads/ displays the proper way. When playing a game, and a spider is killed, the bonus points displays with proper orientation as well.

It's got to be PCB related, but not sure what to be looking at first. Thoughts on what's the cause of this?

Thanks everyone.....
 

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It actually looks like it's displaying some of the characters upside down, rather than backwards, which would make a little more sense (as at least that's more possible, from the internal mechanisms that allow cocktail mode).

Hard for me to say how it might be reading out of memory incorrectly, or only displaying certain columns upside down, but maybe Brian or someone else who knows raster stuff a little better can comment. Interesting issue nonetheless.

Can you post a picture of the test mode screen?
 
Picture of the test screen.

There's a total of 10 beeps.
 

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The beeps are code for bad RAM. See the manual for details.

The RAM chips aren't typically socketed on Centipede boards, so a repair will require desoldering and replacing IC's.
 
Picture of the wire harness PCB. Just a little bit bothersome looking.
 

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That's actually not as bad as I thought you were describing over PM. I thought you were saying they had soldered the wires directly to the board, but I now see I misunderstood, and someone just replaced the edge connector with a solder-terminal type.

That's actually probably not as bad as it looks, if the connections are all ok. It would have been nice if they'd shrink-tubed the connections (just to give them some insulation), but it's unlikely that work is related to the issues you're seeing with the PCB. However, it's worth testing all of the connections, if you're going to run a different good board in that cab. But as long as the voltages are measuring ok on the PCB you have now, you should be ok. You just don't want any wired breaking free and shorting against any of the others.
 
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