This page describes the technical details of the 2025 Swadge's support for the MIDI protocol. Note that while the Swadge only supports the instruments, controllers, and other features described in this document, it can still play any MIDI file, even ones containing unsupported commands. Unsupported commands are simply ignored and the rest of the file will play normally.

Basics

The Swadge's 8-bit audio synthesizer supports up to 16 MIDI channels, with channels 10 and 11 reserved for percussion (the drum kit). By default, channel 1 through 9 are configured to use the MAGFest instruments in order.

Features

24-voice polyphony shared between non-percussion channels
8 additional voices reserved for percussion only channel (channels 10/11 by default)
Pitch bend
AfterTouch

Instrument Banks (Programs)

General MIDI (Bank 0)

For the list of General MIDI instruments available, see Wikipedia. Note that the sound produced for these instruments is a wavetable rather than full-length samples, so they sound more like a retro keyboard than the high-fidelity samples you might hear from a modern soft synthesizer.

GM-Compatible Drum Kit

The Bank 0 Drum Kit is a set of custom drum sounds that follows the standard General MIDI note-to-drum mappings, which can be found on Wikipedia and is commonly supported by MIDI devices and software. Note that some drum sounds may be incomplete or not yet supported. This drum kit is available on MIDI Channel 10.

MAGFest Instruments (Bank 1)

These instruments are mainly basic wave shapes, with some extra goodies thrown in.

Program#	Name
0	Square Wave
1	Sine Wave
2	Triangle Wave
3	Sawtooth Wave
4	"MAGFest Wave"
5	"MAGStock Wave"
6	Noise
7	Square Wave Hit
8	Noise Hit

Donut Swadge Drum Kit

The Bank 1 Drum Kit includes a range of noise-based drum sounds originally featured on the King Donut Swadge. By default, this drum kit is available on MIDI Channel 11.

Note	Note Number	Description
B1 to B2	35 to 47	Donut Drum Kit #1
C2 to C4	48 to 60	Donut Drum Kit #2
C♯4	61	WOAAAGGHHH
D4	72	Donut "MAG"
D♯4	73	Donut "Fest"

MIDI Continuous Controllers

Continuous controller numbers (CC#) are shown here starting from 0. For controllers that have two numbers in the MIDI CC# column, the first number is the "Coarse" (sometimes called "MSB") control, and the second is the "Fine" (sometimes called "LSB") control. These are really two separate controllers analogous to a set of fine and coarse adjustment knobs on a real audio device, but some editing software might display these as a single control instead.

MIDI CC#	Name	Value Range	Description	Notes
0, 32	Bank Select	0-1	Selects the instrument bank used.	Only Fine adjustment (32) is used, Coarse (0) is ignored
7, 39	Channel Volume	0-127	Sets volume level for only this channel	Only Coarse adjustment (7) is used, Fine (39) is ignored
64	Hold Pedal	0-63 (off), 64-127 (on)	When the hold pedal is enabled, all notes that are currently playing are sustained until the hold pedal is released, as well as any notes that begin playing while the hold pedal is already down.
66	Sustenuto Pedal	0-63 (off), 64-127 (on)	When the sustenuto pedal is enabled, only the notes that are currently playing are sustained until the sustenuto pedal is released. Notes that begin playing while the sustenuto pedal is already down are not affected.
72	Release Time	0-127	Set the length of time (in 10ms increments) it will take for a note to fade out and stop playing after it is released.
73	Attack Time	0-127	Set the length of time (in 10ms increments) it will take for a note to reach its maximum volume after it starts playing.
75	Decay Time	0-127	Set the length of time (in 10ms increments) it will take for a note to fade from its maximum volume to its sustain volume.
76	Sustain Level	0-127	Set the volume level the note will reach at the end of the decay time, and will be maintained as long as the note is held on.
6, 38	Data Entry	0-16383	Set the value of the registered or non-registered parameter that was selected previously using the `Registered Parameter` or `Non-registered Parameter` controllers.
96	Data Button Increment	0 (not used)	Increments the value of the registered or non-registered parameter by one
97	Data Button Decrement	0 (not used)	Decrements the value of the registered or non-registered parameter by one
98, 99	Non-registered Parameter	0-16383	Selects a non-registered parameter to be changed with the `Data Entry`or `Data Button` controllers.
101, 100	Registered Parameter	0-16383	Selects a registered parameter value to be changed with the `Data Entry` or `Data Button` controllers.

MIDI Non-registered Parameters

These parameters can be changed by first using the Non-registered Parameter controller to select a specific parameter, then using the Data Entry or Data Button controllers to actually change the parameter's value.

MIDI NRPN#	Name	Value Range	Description
10	Percussion	0 (off), 1 (on)	Sets whether this channel plays a drum kit instead of a pitched instrument

MIDI System-Exclusive (SysEx) Parameters

The Swadge does not currently support any SysEx commands of its own, but it does support the following Universal SysEx commands.

Name	Data (Hex)	Description
GM Enable	F0 7E 7F 09 01 F7	Enables General MIDI Mode. All channels are fully reset, and set to use Bank 0, Program 0 ("Acoustic Grand Piano"), and Channel 10 only set to Percussion mode.
GM Disable	F0 7E 7F 09 00 F7	Disables General MIDI Mode. All channels are fully reset, and set to use Bank 1. Channels 1 through 9 are set to use Programs 0 through 8, respectively. Channel 10 is set to Percussion mode, and set to Bank 0 (General MIDI Compatible Drum kit). Channel 11 is set to Percussion mode, and set to Bank 1 (Donut Swadge Drum kit). Channels 12 through 16 are currently set to Bank 0, Program 0 ("Acoustic Grand Piano"), but note that this may change in the future and is not a guarantee.