Chips › Sound & audio › Wavetable & sample › Ricoh NES APU
Ricoh NES APU
1983
Ricoh's Audio Processing Unit inside the NES CPU, producing the console's two pulse, triangle, noise and DPCM sound channels.
Emulators
| Emulator | Type | License | Site |
|---|---|---|---|
| FCEUX | downloadable | GPL-2.0 | Website ↗ |
| JSNES | online | GPL-3.0 | Website ↗ |
| Jnes | downloadable | Freeware | Website ↗ |
| Mesen | downloadable | GPL-3.0 | Website ↗ |
| NESbox | online | MIT | Website ↗ |
| NESticle | downloadable | Freeware | Website ↗ |
| Nestopia | downloadable | GPL-2.0 | Website ↗ |
| Nestopia UE | downloadable | GPL-2.0 | Website ↗ |
| Nintaco | downloadable | Freeware | Website ↗ |
| Nintendulator | downloadable | GPL-2.0 | Website ↗ |
| VirtuaNES | downloadable | Freeware | Website ↗ |
| ares | downloadable | ISC | Website ↗ |
| higan | downloadable | GPL-3.0 | Website ↗ |
| nemulator | downloadable | Freeware | Website ↗ |
| puNES | downloadable | GPL-2.0 | Website ↗ |
Reference & documentation
External technical references for programming Ricoh NES APU and for writing emulators.
| Resource | Type | Notes |
|---|---|---|
| 2A03 technical reference ↗ | Datasheet | Pins, sound microarchitecture, register-level details |
| APU DMC - NESdev Wiki ↗ | Format | DPCM 1-bit delta sample format, rate tables |
| APU Frame Counter - NESdev Wiki ↗ | Interrupt list | Frame IRQ timing, 4/5-step sequencer modes |
| APU registers - NESdev Wiki ↗ | Memory map | Bit layouts for $4000-$4017 sound registers |
| 2A03 technical reference - pinout ↗ | Pinout | 40-pin 2A03 pinout diagram |
| APU period table - NESdev Wiki ↗ | Programming | Note-to-period lookup tables with generator script |
| NES APU Sound Hardware Reference (blargg) ↗ | Reference | Hardware-tested authoritative APU behavior reference |
| APU Mixer - NESdev Wiki ↗ | Reference | Nonlinear DAC output-mixing formulas and lookup tables |
| APU - NESdev Wiki ↗ | Reference | Overview of all five APU channels |
| nes-test-roms (christopherpow) ↗ | Test suite | Canonical collection of NES emulator test ROMs |
| nes-audio-tests (bbbradsmith) ↗ | Test suite | DAC linearity and expansion-audio comparison ROMs |