Gate Trigger Modes
The midiDAC allows the selection of two gate trigger modes via the ‘Legato mode’ switch.
This is marked on the new PCB as ‘RE-TRIG’. You can connect a simple SPST switch to this
or a simple jumper. The setting of this switch/jumper determines how the gate signal responds
to overlapping notes. Closing this switch, or fitting the jumper, enables multiple gate
triggering for legato playing. This is the re-trig option. The gate signal is taken briefly low at
the start of a new note, even if the fingers haven’t left the keyboard from the previous note.
With the switch open, or leaving the position blank, the gate does not retrigger for
overlapping notes. This is the classic analogue keyboard method and more suitable for those
TB303 slides.
Legato Mode may also be enabled or disabled via the Legato Footswitch MIDI messages. If
these messages are to be used, the Slide Mode switch on the midiDAC unit should remain in
the off position.
midiDAC Implementation of MIDI Controllers
The following table summarises the MIDI controllers supported by the midiDAC firmware.
Hex
Dec
Midi Controller Definition Implementation on the midiDAC
41h
65
Portamento (Slide)
On / Off Switches the portamento (slide)
function
44h
68
Legato Footswitch
Controls the gate retrigger mode.
0 to 63 = off, 64 to 127 = on.
78h
120
All Sound Off
Silences all notes & clears
accent/gate/slide.
Data byte = 0 for this controller.
79h
121
Reset All Controllers
Centres Pitch Wheel and zeroes various
controllers.
Data byte = 0 for this controller.
7Bh
123
All Notes Off
Silences all notes & clears
accent/gate/slide.
Data byte=0 for this controller.
7Ch
124
Omni Mode Off
Unit responds only to selected MIDI
channel.
Data byte=0 for this controller.*
7Dh 125
Omni Mode On
Unit responds to any MIDI channel. Data
byte=0 for this controller.*
7Eh
126
Poly Mode Off
All notes cleared*
7Fh
127
Poly Mode On
All notes cleared*
* In accordance with MMA specifications, all notes are cleared when these controller
messages are received.
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