NES CPU Specifications
!!! NTSC ONLY !!!
The NES CPU is basically a customized 6502 processor. It runs at 1.79 MHz in NTSC and is manufactured by Ricoh. The CPU is referred to as the 2A03 and is a custom designed chip made by Nintendo. There are two key differences between Nintendo's implementation compared to the traditional 6502 CPU:
1. The 2A03's 6502 core does not perform operations in decimal mode. (BCD)
2. The 2A03 also contains an APU which is referred to as the RP2A07.
Source: http://wiki.nesdev.com/w/index.php/CPU
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