The C74-6502 is a homemade implementation of the venerable MOS 6502 microprocessor. The 6502 was revolutionary in its time, and widely adopted in early home computers and gaming consoles. This design is a microprogrammed, discrete-component 6502, an architecture that was prevalent in 1970s-era mainframe computers which pre-dated modern microprocessor technology.
The C74-6502 is plug-in compatible with a wide variety of 6502 systems, including classic computers from Commodore and Apple, as well as modern systems based around the 65C02 microprocessor still in production today. This CPU runs at speeds of up to 20MHz (vs. 1 MHz for the original MOS 6502).