Ricoh 2A03

The Ricoh 2A03 or RP2A03 (NTSC version) / Ricoh 2A07 or RP2A07 (PAL version) is the 8-bit microprocessor in the Nintendo Entertainment System video game console. It was manufactured by Ricoh. It contained a second-source MOS Technology 6502 core, lacking the 6502's binary-coded decimal mode, with 22 memory-mapped I/O registers that controlled Programmable Sound Generators, rudimentary DMA, and game controller polling.

Regional variations

European and Australian versions of the NES used the Ricoh 2A07 or RP2A07 processor, which was identical to the 2A03 except for a different clock divider and different audio frequency lookup tables to account for the 50Hz vertical refresh rate used in the PAL television standard.

See also

• Nintendo Entertainment System technical specifications

References

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