Questions tagged [6502]

For 6502 series of processors, including hardware and assembly language questions. Use with [hardware] for the hardware interface in particular.

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Why did some MOS 6502 packages have holes in them?

Someone was recently selling an early MOS 6502 CPU on Ebay (date code 0277) in a ceramic package that had a couple of holes in it. You can see them clearly (under the tape, which presumably was not ...
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Why does the JSR operation not jump?

I am building a computer based on the 65C02S, and when stepping through the code, I see strange things happening. This is my code: SEI CLD LDX #$ff TXS JSR someRoutine ... This translates to this ...