Ricoh 2A03

Ricoh 2A03 or RP2A03 is the NTSC version of the 8 -bit microprocessor of the game console Nintendo Entertainment System ( NES), manufactured by Ricoh. It contained from a second source of a 6502 - core, lacking the BCD mode of 6502. To control the programmable tone generators he had 22 memory mapped I / O registers, rudimentary DMA and polling for the game controller.

Regional variations

European and Australian versions of NES used Ricoh 2A07 or RP2A07 processor, which is identical to the 2A03, to identify up to another frequency divider, and various low-frequency lookup tables, the 50 Hz vertical frequency, which are used in the PAL standard.