PUNCH — twelve OPL2-style percussion engines for the Model:Cycles

PUNCH is one added machine for the Elektron Model:Cycles, OS 1.13: twelve percussion voices built on a two-operator FM engine in the manner of the Yamaha OPL2, with extended fixed ratios for modern sounds and alien harmonics. Raw, heavy and digital.

This repository is the machine's source package, published so that other projects can port it. It is not a firmware and contains none.

Hear it: PUNCH on YouTube
Flasher: 100demons.github.io/cycles-engines/flasher — tick PUNCH and bring your own official model-cycles_OS1.13.syx.

The engines

SHAPE picks the engine. The names are shown on the machine's screen.

SHAPE	Engine	What it is
0	KIK	Kick: the classic FM kick, three octaves of pitch drop into a sine body
1	TOM	Tom: tuned membrane, one octave of pitch drop
2	BNG	Bongo: high, short and tight
3	CNG	Conga: lower and rounder, with a short bend
4	DJB	Djembe: hand drum, pitch drop and FM body
5	TAI	Taiko: big low drum, deep pitch drop, FM body
6	TIM	Timpani: felt thud and a long membrane
7	MAR	Marimba: fundamental plus tuned overtone, mallet click
8	BLK	Woodblock: short, hard pitched click
9	GNG	Gong: low inharmonic metal, long FM decay
10	BUB	Bubble: pitch rises into the note
11	ZAP	Laser: four-octave pitch fall

The knobs

Knob	What it does
PITCH / FINE	the note, as on every machine
COLOR	the FM depth
SHAPE	the engine (the table above)
SWEEP	the ratio, 1:4 to 15X, stepped
CONTOUR	shapes the model's movement
DECAY	the decay, or release when GATE holds the note
GATE	on: holds the note for its length
PUNCH	on: MAR gets vibrato, GNG gets tremolo; the other engines ignore it

Status

Package	cycles-mod/0.1, the model27/cycles-engines package format
Slot in the flasher	8 (the OS numbers it machine 7)
Committed object	punch.o; core/build_engine.py punch --check passes
Emulated	a voice-loop test exists in the source tree; this package's manifest records no date
Tested on a real Model:Cycles	not yet
License	MIT

PUNCH makes its own envelopes; the stock amp chain is not called. A silent voice is not computed. The OS still sets the volume and applies velocity after the voice.

Package layout

tools/machines/punch/
  manifest.json    the package: build recipe, symbols, claims, tests, compatibility
  card.json        the flasher card: label, description, status, video
  punch.c          the voice-loop bridge
  punch_dsp.h      the FM engine (two operators, OPL2-style log-sine and power tables)
  punch_tables.h   the generated tables
  punch_icons.h    the splash artwork
  punch.o          the committed relocatable object
  LICENSE          MIT

There is no firmware here: the package is applied to the user's own official OS file by a host such as cycles-engines.

Build and check the object

The package builds with the cycles-engines toolchain. Copy tools/machines/punch/ into a cycles-engines checkout as engines/punch/, then:

export M68K_CROSS=/path/to/bin/m68k-elf-        # or have m68k-elf-gcc on PATH
python3 core/build_engine.py punch --check

--check rebuilds punch.o from punch.c and the manifest's recipe and compares it with the committed object. The composer and the flasher never need the toolchain: they place the committed object.

Install

Easiest: tick PUNCH in the flasher and bring your own official OS 1.13 file. Or download punch-1.0.zip from this repository's Releases and add the folder to your own build.

Credits

• Engine, tables and design: 100demons, MIT.
• The OPL2 is named as the synthesis model; no Yamaha code, ROM dump or sample is included. See THIRD-PARTY-NOTICES.md.

Changelog

See CHANGELOG.md.