Professional software development, amateur BMW tinkering, old arcade game stuff


Capcom Tiger Road arcade pcb repair

This game had every second scanline missing in all the sprites.

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A lot of arcade game games work by using two line RAM buffers for sprites – the sprite logic builds line N+1 in RAM0 whilst line N in RAM1 is displayed to the screen, then they swap and RAM0 outputs to the screen whilst the new line is built in RAM1 and so on.

So a missing scanline in sprites suggests one of the RAM chips in the double buffer has failed.  By piggybacking good RAM onto the chips on the video board I found the fault right away.  The lower line buffer RAM had failed.  A new one was soldered in and game fixed.

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