THE HARDWARE
Four consoles, four very different sound chips. Each one is rebuilt in code and checked against a real unit - pick a card to hear it and see how close the emulation gets.
Thin, bright square waves and a gritty noise channel - the sound of the earliest home consoles.
The Ricoh 2A03 has five voices: two pulse (square) wave channels, one triangle wave channel, one noise channel, and one channel that plays short sampled hits.
A softer, more muffled square wave than the 2A03, with a four-bit programmable wave channel for a rounder tone.
The Game Boy's sound hardware has four voices: two pulse wave channels, one programmable wave channel that can hold any four-bit waveform, and one noise channel.
Metallic, percussive FM tones layered with punchy square-wave chords - two very different chips sharing one mix.
The Sega Mega Drive carries two sound chips: the Yamaha YM2612 has six FM voices (one is often reassigned to play sampled drums instead), and the Texas Instruments SN76489 adds three square-wave tone channels and one noise channel - up to ten voices in total.
Rounder and closer to real instruments than the other three - every voice plays back a short recorded sample, not a waveform.
The Super Famicom's S-DSP has eight sample-based voices, each with its own pitch, volume and ADSR envelope, plus a built-in echo/reverb effect shared by the whole mix.