The Famicom's voice: a Ricoh 2A03 - or its PAL twin, the 2A07 - with a cartridge slot. The console chip alone is five voices: two pulse waves with the four hardware duty cycles, the bare 4-bit staircase triangle, the LFSR noise channel, and the 1-bit delta sampler. Slot in a cartridge and its expansion audio joins the pool, the way Famicom games wired extra synthesizers through the cart connector. The emulation is NSFPlay's, driven register by register.
The console
Two pulses take your notes first, oldest note stolen when the chip runs out. **Duty** picks their width - the hardware's own 12.5, 25, 50 and 75 percent - and the ADSR shapes them in the chip's sixteen volume steps, ticked at frame rate the way NES drivers actually articulated notes, so a fast attack snaps and a slow one climbs the staircase audibly.
| Triangle | shadows the lowest held note an octave of body below the pulses. The hardware gave it no volume knob, so neither do we: it is on or off, and that is its charm. |
| Noise keys | : C7 and up play the noise channel instead of a tone, stepped down the hardware's sixteen periods as you go up the keys. **Buzz** flips it into the short-loop mode - the metallic 93-step rattle instead of white wash. |
| Sample | loads any sound into the delta channel: it is crushed to 1-bit DPCM, exactly the format the console streamed, and keys below C2 fire it at the hardware's sixteen playback rates - your kick on B1, pitched down from there. **Loop** holds it while the key is held. |
The cartridges
| VRC6 | - two more pulses with finer widths and the famous sawtooth: three extra voices. |
| MMC5 | - two more straight pulses. |
| FDS | - the disk system's wavetable voice; **Wave** picks its table. |
| N163 | - four wavetable voices from the multiplexed Namco chip, same **Wave**. |
| 5B | - three flat PSG squares. |
| VRC7 | - six two-operator FM voices; **Patch** picks among the chip's fifteen built-in instruments. |
One cartridge sits in the slot at a time; changing it silences held notes, like swapping the game.
Parameters
| Region | is the console itself: NTSC (2A03) or PAL (2A07) - clock, pitch tables and envelope tick all follow, so PAL runs a shade slower and darker, as it did. |
| Attack / Decay / Sustain / Release | count in frames per volume step, sixteen levels top to bottom. **Level** is the output volume; the mix uses the console's nonlinear DAC curves, so channels crowd each other exactly as they did on hardware. |