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Author Topic: Rock Climber  (Read 2408 times)
tim
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« on: November 20, 2005, 05:04:22 PM »

Symptom
Screen full of static garbage. No boot.

Tests
Hooked up Z80 logic analyzor. No activity on CPU at all. Reset line held low immediately from power on. Traced reset
line to output pin of a 7404 on the middle board. Two inputs must be low for output to go high. One input was toggling
and the other was floating. Traced floating input back to pin 22 on main edge connector.

Fix
Grounded pin 22 and game booted. Must be a -sense pin that gets pulled low by the game's original harness. We don't need no stinking pinouts. Grin
« Last Edit: November 22, 2005, 11:15:26 AM by tim » Logged
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