MGB

mGB
General
Author	trash80
Type	Music Apps
Version	1.3.3
License	GPL-2.0
System	DMG, CGB
Last Updated	2012/12/21
Links
Download
Website
Source

mGB is a Game Boy cartridge program (you need a Flash Cart and Transfer hardware) that enables the Gameboy to act as a full MIDI supported sound module, turning the Game Boy into a MIDI synthesizer.

mGB works with the old DMG Gameboy as well as GBC/GBA. It was originally developed for Arduinoboy, a device using a Arduino (developped by Trash80) that enable MIDI capabilities for a old Nintendo GameBoy using special software such as LSDJ, nanoloop and mGB.

User guide

MIDI Implementation

Note: the name and number at the bottom left of the screen indicates the midi CC of the selected parameter.

PU1 - MIDI CH1:

• Program Change: 1 to 15.
• PB: Pitch bend - up to +/- 12.
• cc1: Pulse width - 0,32,64,127.
• cc2: Envelope mode - 0 to 127, 16 possible steps.
• cc3: Pitch sweep.
• cc4: Pitchbend Range.
• cc5: Load Preset.
• cc10: Pan.
• cc64: Sustain- Turns off note off. <64 = off, >63 = on.

PU2 - MIDI CH2:

• Program Change: 1 to 15.
• PB: Pitch bend - up to +/- 12.
• cc1: Pulse width - 0,32,64,127.
• cc2: Envelope mode - 0 to 127, 16 possible steps.
• cc4: Pitchbend Range.
• cc5: Load Preset.
• cc10: Pan.
• cc64: Sustain- Turns off note off. <64 = off, >63 = on.

WAV - MIDI CH3:

• Program Change: 1 to 15.
• PB: pitch bend - up to +/- 12.
• cc1: shape select : 16 possible on a 0 to 127 range.
• cc2: shape offset : 32 possible on a 0 to 127 range.
• cc3: Pitch Sweep speed. 0=Off, 1-127 speed.
• cc4: Pitchbend Range.
• cc5: Load Preset.
• cc10: pan.
• cc64: Sustain- turns off note off. <64 = off, >63 = on.

NOISE - MIDI CH4:

• Program Change: 1 to 15.
• PB: pitch bend +/-24.
• cc2: envelope mode - 0 to 127, 16 possible steps.
• cc5: Load Preset.
• cc10: pan.
• cc64: (sustain) turns off note off. <64 = off, >63 = on.

POLY MODE - MIDI CH5 - Plays Pu1/Pu2 and Wav in poly:

• Pogram Change: 1 to 15.
• PB: pitch bend +/-2.
• cc1: See cc1.
• cc5: Load Preset.
• cc10: pan.
• cc64: (sustain) turns off note off. <64 = off, >63 = on.

Controls

Start - MIDI Panic

Select+D-Pad - Select multiple synths for editing

Select+A - Toggles the screen on or off, better battery life, less noise, and faster response

Select+B - Copys all parameters on screen while cursor is not on preset number

B - Pastes all parameters while cursor is not on preset number

A+D-Pad - Change parameter value

To load/save presets, put the cursor on the "PRESET" number, and hit B for load, Select+B to save.

Media

Use your Gameboy as a MIDI instrument (8-Bit Keys)

JAMATAR - Midori 【MGB / Gameboy / Chiptune】 (JAMATAR)

Changelog

2015/06/26

• Project has been moved to GitHub along with sourcecode.

1.3.3 2012/12/21

• Fixed a bug with the new pitchbend resolution.
• Optimized some of the pitchbend routine.

1.3.2 2012/12/20/12

• Increased pitchbend resolution.

1.3.1 2012/12/19

• Fixed PU1 Envelope retrigger bug.

1.3.0 2009/02/02

• Rewrote 90% of code into assembly for much faster performance- especially noticeable on DMG.
• Changed note behavior. Removed Monophonic note memory to increase performance.
• Envelope does not retrigger if the notes overlap and have the same velocity- Good for arpeggios / broken chords.
• Note off has a slight delay so immediate retrigged notes don't cause "clicking" effect due to turning off the synth.
• Added screen off mode for great signal-to-noise ratio, longer battery life, and better performance on DMG. (To toggle the screen mode hold Select and press A.)
• Created back-end routine that prioritizes processes for better performance.
• Added 8 "noise" shapes to the Wav synth for more interesting effects.
• Made Wav pitch sweep stable and changed it so it glitches out at values above 8.

1.2.4 2008/11/05

• Fixed small bug with the indicator arrow, it was offset vertically a bit.
• Fixed bug with unexpected behavior with large PB Ranges.
• PB Range Max is now 48 notes. (hehe)
• Octave Shift max is now -2/+3
• Added some Octave shift logic. If the current note is greater than what the GB can play due to octave shifting, it will select the lower octave note, so no off key notes will play.
• Added Gameboy Color fast-cpu mode- better performance with newer Gameboys.

1.2.3 2008/10/28

• Added Note markers above synth number, so you can tell if the synth is on.
• Added PB wheel reset to MIDI panic (Start button).
• Code more efficient (I'm sure there is still more to do here).
• nitro2k01 @ http://gameboygenius.8bitcollective.com rewrote my gamejack serial function to make it as fast as possible. Thanks!

1.2.2 2008/10/25

• Added Program Change messages to mGB.
• Rewrote MIDI data input for mGB. (Rewrote the function in ASM to make it faster).
• Added Controller Priority. While changing parameters on the gameboy itself, MIDI messages will not overwrite your changes while your editing them. This is a good live mode feature.

1.2.1 2008/10/23

• Found & Fixed various bugs in 1.2.0.
• Changed help text. Made it more clear.

1.2.0 2008/10/23

• Change interface a bit.
• Added presets.
• Optimized code.

1.1.0 2008/10/10

• Added Interface.
• Changed Wav CCs Around to make more consistent with the Pu Synths.

0.1.2 2008/10/04

• Fixed bug with Wav Synth hanging after sequencer stop.
• Fixed bug with Wav Synth not resetting monophonic keyboard note triggers.

External links

• GitHub - https://github.com/trash80/mGB