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Old 22nd Sep 2017, 9:19 pm   #30
cmjones01
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Join Date: Oct 2008
Location: Warsaw, Poland and Cambridge, UK
Posts: 2,669
Default Re: Help with 6802 Microcontroller

Some oddness on the data bus is normal: remember that it can be driven by different devices on the bus at different times, so there isn't always anything actually driving it. That means that a certain amount of 'floating' will usually be visible at some stage in the clock cycle. It's not usually anything to worry about.

If the PIA is generating interrupts constantly, find out why: what can cause an interrupt to be generated? Pin change? A particular input? Is it a 6821?

Chris
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