4 HP controller and instrument gateway

MIDI

MIDI receives controller edits, clock, transport, and presets, then emits per-head notes or 7-bit CC. It is transparent to head numbering.

Placement and activity

Place MIDI directly left of Program and directly right of the heads. The green IN light reports accepted input, yellow CLK reports MIDI Clock, and red OUT reports emitted notes or CC.

Device and channels

Traffic	Channel
Program controls and presets	Channel 16 by default; configurable 1–16 in the context menu.
Stage sliders	Channel 15 by default; configurable 1–16. It must differ from the Program channel.
Head 1–8 controls	Fixed channels 1–8 respectively.
Head All controls	Fixed channel 9; CC 0–12 broadcast to all Heads.
Clock and transport	MIDI System Realtime; channel-independent.
Head output lanes	Independently selectable channels 1–16.

Channel 9 reuses CC 0–12 as HEAD ALL commands. CC 13 is ignored on that channel because Display ownership remains exclusive to one Head. Channels 10–14 remain free under the default allocation.

The Rack MIDI input is forced to All channels so SpaceTime can route Program, stage, and head traffic itself. The panel readout prefixes the current channels with P and S.

Stage sliders

CC range	Target
0–63	Stage 1–64 voltage sliders.
64–127	Stage 1–64 time sliders.

Values map 0–127 across the full slider travel. Move stage sliders with CC updates visible handles; when disabled, MIDI changes the active value while preserving normal takeover.

Program CC

CC	Target
64–65	Select previous / next stage.
66–67	Clear and one-shot all-stage edit arm.
68–71	Quantize, Slope, Range, and voltage Source.
72–76	Limited range offsets −2 through +2.
77–81	Stop, Sustain, Enable, First, and Last.
82–85	Four interval-time ranges.
86–88	Time Source, Pulse 1, and Pulse 2.
89	Key C through B.
90	Major, Minor, or Chromatic scale.
91	Pulse Retrig off / on.

Program Change 1–12 recalls preset slots 1–12 on the Program-controls channel.

Head CC

CC	Target
0	Virtual-clock edge.
1–4	Start, Stop, Advance, Reset.
5	Address.
6	Internal / external address source.
7	Strobe / Sequential / Continuous addressing.
8	Direction.
9	Internal / external / MIDI / virtual clock source.
10	Clock divide / multiply.
11	Time CV amount.
12	One-shot / First–Last / full-chain loop mode.
13	Display latch.

Realtime clock and transport

F8 supplies MIDI Clock to heads whose clock source is MIDI. FA Start, FB Continue, and FC Stop affect only heads with Follow MIDI transport enabled.

The current implementation advances from individual F8 edges through the Head Div/Mult setting. A separate musical 24 PPQN interpretation layer is not part of version 2.0.0.

Per-head output

Configure each of eight lanes from HEAD n output in the context menu.

Mode	Behavior
Off	No output; any active note is released.
Notes	Quantized Head CV becomes MIDI note number with 0 V = note 60. Gate source is Pulse 1, Pulse 2, or All.
CC 7-bit	Head CV becomes the selected CC, send-on-change with a short throttle.

Pulse 1/2 notes end on gate fall. All produces a fixed 30 ms note. Unquantized stages do not emit notes.

Deferred MIDI features

14-bit CC, NRPN, note input, MIDI learn, and MIDI-clock output are intentionally outside the 2.0.0 scope.