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:
C74-6502 CPU 