williams flash sys 6. Currently have only thing in, leons rom. The only other thing connected to the data bus is ic18 pia display, buffers are jumperd(and the rom). The problem occurs when any line on the data bus is pulled up to 5v through a 4.7k resistor. Ill investigate further, but any help would be great
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i can't tell if what you are saying the data bus is shorted to ground or not, but i would start removing things until i find the short in the bus, these boards are not complicated or very complex
i guess verify the 6800 cpu is good for starters (if thats what it uses - i don't remember off the top of me head 6800 or 6802/8)
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Perth
Meridian, ID