Big Game
Stern Electronics, 1980You're currently viewing posts by Pinsider dr_dude.
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Immediate crash after 7-flashes is, in my experience, possibly due to bad NMI (Non-Maskable Interrupt) from the 555 timer IC (little 8-pin DIP). The NMI is supposed to tell the MPU to scan the switch-matrix, and strobe the displays, lights, etc., but if it's coming too fast it will crash the 6800. Could be the 555 itself, or associated capacitors/resistors. Alas, short of shotgunning parts (replace and see if it helps), you'd need a scope to diagnose this failure.
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Ottawa, ON
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