RP2A03G
About this component
The 2A03 is the NES's main processor. It runs game code from the cartridge, generates all five sound channels (two pulse, triangle, noise and DPCM) on its AD1/AD2 pins, strobes the controller ports and copies sprite data to the PPU by DMA. It sits in a 40-pin DIP soldered to the board; before suspecting it, check the audio output circuit for no-sound faults and the MN74HC368 buffer chips (U7, U8 on NES-CPU-07) for controller faults. PAL machines use the RP2A07, which is not a drop-in swap for an NTSC console because the clock and timings differ. Part variants: Early NES-001 units carry RP2A03E (seen 1984-86); RP2A03G from 1987 to 1993 (found on NES-CPU-07); RP2A03H on late units. PAL consoles use the RP2A07 instead.
MOS 6502-based CPU @1.79MHz with an integrated APU for sound.
Pinout & readings
No pinout or reference readings yet — these show what each pin does and what a healthy part should measure.