After two years of work, finally it was time for the ultimate test of compatibility: would the C74-6502 be able to replace the microprocessor inside a genuine vintage 6502 computer? A 1983 VIC-20 is a fitting machine to use for this test. The VIC-20 is an iconic device — it set the standard for early home computers and was the first computer of any kind to sell over a million units.

Successfully replacing this machine’s MOS 6502 microprocessor would mean that the C74-6502 is functionally equivalent to the original, and a deserving bearer of the 6502 designation. A photo-blog below documents the occasion:

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C74-6502 Ready For Duty
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VIC 20’s MOS 6502 Microprocessor
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C74-6502 Transplant Complete
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Victory! — It Works
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Programming With The C74-6502
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Playing “Frogger” — A Classic
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Testing With Other Games
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C74-6502 Pays Homage To The Original