|Produced||From 1982 to 1995|
|Max. CPU clock rate||1.79 MHz|
|Min. feature size||6 ?m|
|Instruction set||MOS 6502|
The Ricoh 2A03 or RP2A03 (NTSC version) / Ricoh 2A07 or RP2A07 (PAL version) is an 8-bit microprocessor manufactured by Ricoh for the Nintendo Entertainment System video game console. It contained a second sourced MOS Technology 6502 core, modified to disable the 6502's binary-coded decimal mode, with 22 memory-mapped I/O registers that controlled an APU, rudimentary DMA, and game controller polling. It was also used as a sound chip and secondary CPU by Nintendo's arcade games Punch-Out!! and Donkey Kong 3.
PAL versions of the NES (sold in Europe, Asia, and Australia) used the Ricoh 2A07 or RP2A07 processor, which was identical to the 2A03 except for a different clock divider and the 50 Hz vertical refresh rate used in the PAL television standard, with the exception of the 16 hard-coded sampling rates for the Delta modulation-encoded sample playback unit. The changes were made in order for sampled sounds to maintain the original pitch of the RP2A03 with the new clock divider.
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