The C74 Project aims to build a Commodore C64 using only 7400 Series discrete components. The C74-6502 CPU is the first step in this larger effort, and it took over three years to complete. Other ICs in the C64 include the notoriously complex VIC and SID chips, among others, and these are easily as difficult to render in discrete logic as the CPU itself. This project is certain to be a long road.
Acknowledgements For “OurCPU”
The C74-6502 project began as a novice attempt to build a working TTL 6502. From the start, the design relied on Dieter Mueller’s Multiplexer ALU and BCD circuitry, as well as a myriad of articles and information found on 6502.org. The design advanced significantly when 6502.org forum members ttlworks (Dieter Mueller) and Dr Jefyll (Jeff Laughton) jumped in to help. The project then evolved as a team effort – hence “OurCPU”.
I cannot thank Dieter and Jeff enough for their generous collaboration, expert mentoring, and good humour — I am indebted to them both. A special thanks as well to all the folks at 6502.org who together make up such a welcoming and supportive community.
- Project Forum Thread (on 6502.org)
- Dieter Mueller (ttlworks on 6502.org)
- Jeff Laughton (Dr Jefyll on 6502.org)
- Ed Spittles (BigEd on 6502.org)
- Garth Wilson (GARTHWILSON on 6502.org)
- BDD’s POC1 and POC2
- Bruce Clarke 6502 Decimal Mode, V Flag, 65C02 Opcodes
- Klaus Dormann’s 6502 Test Suites
- Arlet Ottens 6502 Verilog Core
- Visual 6502
- Unintended Opcodes – No More Secrets