GM programs 0-15
Pulse, 50% duty
Envelope
Spectrum
- Attack
- 3 ms
- Decay
- 98.8 ms
- Release
- 10.9 ms
- Peak / RMS
- -12.6 / -31.5 dBFS
- Spectral centroid
- 564 Hz
- Noise vs. tone
- tonal
MACHINE
Game Boy DMG APU
A softer, more muffled square wave than the 2A03, with a four-bit programmable wave channel for a rounder tone.
ITS VOICES
How it makes sound.
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.
chipvoice uses the pulse channels for melody and chords, the wave channel for bass, and the noise channel for drums.
HEAR EVERY PRESET
Its instruments.
Every preset a user can pick for this chip - played as one fixed probe, measured, never typed by hand.
Melody
GM programs 16-127
Pulse, 25% duty
Envelope
Spectrum
- Attack
- 3 ms
- Decay
- 92.8 ms
- Release
- 9.4 ms
- Peak / RMS
- -12.6 / -33.0 dBFS
- Spectral centroid
- 716 Hz
- Noise vs. tone
- mixed
GM programs 32-37
Wavetable, 32 steps
Envelope
Spectrum
- Attack
- 3 ms
- Decay
- 3 ms
- Release
- 15.4 ms
- Peak / RMS
- -14.3 / -22.4 dBFS
- Spectral centroid
- 582 Hz
- Noise vs. tone
- tonal
GM programs 38-39
Wavetable, 32 steps
Envelope
Spectrum
- Attack
- 3 ms
- Decay
- 3 ms
- Release
- 15.4 ms
- Peak / RMS
- -14.3 / -22.4 dBFS
- Spectral centroid
- 582 Hz
- Noise vs. tone
- tonal
GM programs 40-87
Pulse, 25% duty
Envelope
Spectrum
- Attack
- 3 ms
- Decay
- 3 ms
- Release
- 12.4 ms
- Peak / RMS
- -14.2 / -23.7 dBFS
- Spectral centroid
- 729 Hz
- Noise vs. tone
- tonal
GM programs 56-63
Pulse, 12.5% duty
Envelope
Spectrum
- Attack
- 3 ms
- Decay
- 3 ms
- Release
- 9.4 ms
- Peak / RMS
- -14.2 / -26.1 dBFS
- Spectral centroid
- 1107 Hz
- Noise vs. tone
- tonal
Chords
GM programs 0-15
Pulse, 50% duty
Envelope
Spectrum
- Attack
- 3 ms
- Decay
- 98.8 ms
- Release
- 10.9 ms
- Peak / RMS
- -12.6 / -31.5 dBFS
- Spectral centroid
- 564 Hz
- Noise vs. tone
- tonal
GM programs 16-127
Pulse, 25% duty
Envelope
Spectrum
- Attack
- 3 ms
- Decay
- 92.8 ms
- Release
- 9.4 ms
- Peak / RMS
- -12.6 / -33.0 dBFS
- Spectral centroid
- 717 Hz
- Noise vs. tone
- mixed
GM programs 32-37
Wavetable, 32 steps
Envelope
Spectrum
- Attack
- 3 ms
- Decay
- 3 ms
- Release
- 15.4 ms
- Peak / RMS
- -14.2 / -22.4 dBFS
- Spectral centroid
- 582 Hz
- Noise vs. tone
- tonal
GM programs 38-39
Wavetable, 32 steps
Envelope
Spectrum
- Attack
- 3 ms
- Decay
- 3 ms
- Release
- 15.4 ms
- Peak / RMS
- -14.2 / -22.4 dBFS
- Spectral centroid
- 582 Hz
- Noise vs. tone
- tonal
GM programs 40-87
Pulse, 25% duty
Envelope
Spectrum
- Attack
- 3 ms
- Decay
- 3 ms
- Release
- 12.4 ms
- Peak / RMS
- -14.2 / -23.7 dBFS
- Spectral centroid
- 729 Hz
- Noise vs. tone
- tonal
GM programs 56-63
Pulse, 12.5% duty
Envelope
Spectrum
- Attack
- 3 ms
- Decay
- 3 ms
- Release
- 9.4 ms
- Peak / RMS
- -14.2 / -26.1 dBFS
- Spectral centroid
- 1107 Hz
- Noise vs. tone
- tonal
Bass
GM programs 0-127
Wavetable, 32 steps
Envelope
Spectrum
- Attack
- 1.5 ms
- Decay
- 3 ms
- Release
- 16.9 ms
- Peak / RMS
- -20.0 / -29.1 dBFS
- Spectral centroid
- 336 Hz
- Noise vs. tone
- tonal
GM programs 38-39
Wavetable, 32 steps
Envelope
Spectrum
- Attack
- 3 ms
- Decay
- 3 ms
- Release
- 15.4 ms
- Peak / RMS
- -20.7 / -29.2 dBFS
- Spectral centroid
- 723 Hz
- Noise vs. tone
- tonal
Drums
Kick
Tone
Envelope
Spectrum
- Attack
- 1.5 ms
- Decay
- 636.1 ms
- Release
- 0.4 ms
- Peak / RMS
- -14.3 / -27.4 dBFS
- Spectral centroid
- 3635 Hz
- Noise vs. tone
- noisy
Snare
Tone
Envelope
Spectrum
- Attack
- 3 ms
- Decay
- 624.1 ms
- Release
- 7.9 ms
- Peak / RMS
- -15.1 / -27.7 dBFS
- Spectral centroid
- 2177 Hz
- Noise vs. tone
- noisy
Hi-hat
Noise
Envelope
Spectrum
- Attack
- 6 ms
- Decay
- 630.1 ms
- Release
- 0.4 ms
- Peak / RMS
- -20.3 / -33.3 dBFS
- Spectral centroid
- 829 Hz
- Noise vs. tone
- mixed
Open hi-hat
Noise
Envelope
Spectrum
- Attack
- 4.5 ms
- Decay
- 655.5 ms
- Release
- 0.4 ms
- Peak / RMS
- -18.7 / -31.0 dBFS
- Spectral centroid
- 1110 Hz
- Noise vs. tone
- mixed
HOW WE CHECK
Its evidence.
How closely this chip's emulation matches the real hardware, from the conformance harness that runs before each release.
Digital parity
Compared with Gb_Snd_Emu 0.1.4 (blargg): 57.3 % identical (83,100,392 of 145,122,916 cycles), 7 of 7 logs with any divergence.
First divergence: script-envelopes, cycle 419432, ch1 - ours 0, the oracle's 15.
Compared with SameBoy (DMG-B): 94.8 % identical (137,606,353 of 145,122,916 cycles), 6 of 7 logs with any divergence.
First divergence: script-envelopes, cycle 427391, ch1 - ours 15, the oracle's 0.
Test ROMs
12 of 12 test ROMs pass.
- dmg_sound/01-registers: pass
- dmg_sound/02-len_ctr: pass
- dmg_sound/03-trigger: pass
- dmg_sound/04-sweep: pass
- dmg_sound/05-sweep_details: pass
- dmg_sound/06-overflow_on_trigger: pass
- dmg_sound/07-len_sweep_period_sync: pass
- dmg_sound/08-len_ctr_during_power: pass
- dmg_sound/09-wave_read_while_on: pass
- dmg_sound/10-wave_trigger_while_on: pass
- dmg_sound/11-regs_after_power: pass
- dmg_sound/12-wave_write_while_on: pass
Analog stage
Not measured yet. This stage is a placeholder, not a result.
Driver coverage
The shipped driver reaches 4 of the chip's 4 voices.