STUTTERDS

Buttons

▲▼◀►

D-pad - move the cursor on every screen. Auto-repeats while held.

A

Edit modifier. In PATTERN: A + Up/Down cycle the cell value, A + Left/Right nudge the cell's per-cell octave (-2..+2). A+B (either order) DELETES the cursor cell - works on note OR inst sub-row. A+R pastes the row clipboard. In SONG: A + Up/Down cycle the song cell's pattern number. In LAB: held alone or with L/R to nudge a parameter value. In PERFORM: capo glitch (see Glitch section).

B

In PATTERN: on the inst sub-row opens the INSTRUMENT LAB for that inst; on the note sub-row B alone is a no-op (delete is the dedicated A+B combo now, so a stray B can't wipe a note you were auditioning). In SONG: B alone clears the cell. In PERFORM: live-arp modifier (B + dir picks UP/DOWN/TRI/RANDOM).

X

In EDIT: tap toggles FOCUS between the top tracker and the bottom song arranger. In PERFORM: tap still toggles focus; hold = stutter (32nd-note retrigger of the current step).

Y

In PATTERN: Y + Left/Right step the edit pattern. Y+B (either order) pastes the last entered value -- last note on the note sub-row, last instrument on the inst sub-row. In PERFORM: Harmony modifier - momentary transpose that sums with the A capo (see Glitch section).

L

Toggle PERFORM mode (D-pad and face buttons become live glitch triggers).

R

Copy cursor's voice row to the row clipboard. A+R = paste.

SELECT

In SONG focus: open SETTINGS overlay. In PATTERN focus: open COPY FROM modal. A+SELECT: open RANDOMIZE modal. Inside the lab: open COPY FROM patch modal. In PERFORM: flashes a "EXIT PERFORM (L) FIRST" hint -- settings are EDIT-mode only.

START

Play / pause the transport. Hold ~0.4s to restart from song position 0.

Screens & navigation

TOP

Text-mode pattern editor (tracker) + live oscilloscope at the right edge. Overlays here: INSTRUMENT LAB, modals.

BOTTOM

Song arranger by default. Overlays: SETTINGS, PHRASE editor.

FOCUS

One screen owns the cursor at a time. The focused mode label glows bright; the unfocused side dims to grey. Toggle with X.

Help-row indicators

MIDI

Yellow tag on the top help row means the mDS slot-2 MIDI cart was detected; the song clock is locked to it.

scope hue

Right-edge waveform colors itself by the dominant voice: cyan samples, magenta pulse, white noise.

Pattern editor (top)

◀►

Move between the 16 step columns.

▲▼

Walk through all 18 cursor slots (9 voices × note / inst rows).

A+▲▼

Cycle the cell value. Note: REST → 1..12 → X (loop) → S (sustain) → REST. Inst: 0..31.

A+◀►

Step the edit pattern (0..95). Cross-pattern paste lands on the cursor's CURRENT pattern.

A+B

DELETE the cursor cell (any sub-row). Bidirectional edge - A first or B first both fire.

Y+B

Paste the last entered value - note on the note sub-row, instrument on the inst sub-row. Bidirectional edge.

B

Inst row: open the INSTRUMENT LAB for that inst. Note row: no-op.

X (cell)

LOOP marker - silences the row from that step on and wraps the pattern to step 0.

S (cell)

SUSTAIN - hold whatever the voice was already playing; envelope continues, no retrigger.

Voice rows

P1 P2

Pulse (DS PSG square channels). Per-patch duty.

F1 F2

FM (2-op, DS-10 style). Pre-rendered wavetable looped on a PCM channel. Used to be P3 / P4 PSG voices.

N

Noise (PSG noise channels). Variant picks LFSR clock multiplier.

S1 S2 S3 S4

PCM samples (DS PCM channels). Each patch source is PCM slot or SAM phrase.

Per-cell octave color

+2

Bright magenta - two octaves up.

+1

Dim magenta - one octave up.

0

Yellow on every 4th step (beat), white off-beat.

-1

Dim cyan - one octave down.

-2

Bright cyan - two octaves down.

Song arranger (bottom)

◀►▲▼

Move within the 16-cell page; top / bottom wraps to the next page (6 pages, 96 cells total).

A+▲▼

Change the pattern number at the cell (0..95).

B

Clear the cell back to empty.

empty / LOOP

Empty cells wrap to slot 0. LOOP marker (X) also wraps to 0.

play mode

PLAY_SONG vs PLAY_PATTERN. Y starts the song from slot 0 (SONG focus) or loops the edit pattern (PATTERN focus). X-toggle while playing swaps modes live.

Instrument lab

open

B on a PATTERN inst-row cell, or Y on the cursor cell. Takes over the top screen.

▲▼

Move between visible parameter rows.

◀►

Change the value at the cursor row.

A+◀►

Flip through patches in the same bank without leaving the lab. Wraps 0..31.

A

On the PHRASE row of a SAM-source sample patch: open the phrase editor.

SELECT

Open COPY FROM modal: header swaps to COPY src -> dst, D-pad walks the source inst (same bank, wraps 0..31), A overwrites the current patch with the picked one (phrase too, on SAMPLE bank), B or SELECT cancels.

B

Close the lab.

Banks

PULSE

32 patches. Shared by P1 + P2. Variant = duty cycle.

FM

32 patches. Shared by F1 + F2. 2-op carrier+modulator; variant = mod ratio, sweep field = feedback, penv_* fields drive the modulator ADSR.

NOISE

32 patches. Used by N. Variant = LFSR rate multiplier.

SAMPLE

32 patches. Shared by S1..S4. Variant = PCM slot OR SAM phrase preset.

See the Patch codes section below for every parameter and its range.

SAM speech voice

enable

In a sample patch, set SOURCE = SAM. PCM-only rows hide; SAM-only rows reveal.

PHRASE

Up to 31 chars. Press A on this row in the lab to open the editor.

keys

Phrase editor. D-pad: Up/Down cycle the letter at the cursor (A..Z + space + .?!,'); Left/Right move the cursor. L = insert space, R = backspace. A = ok, B = cancel.

input

English vs phonemic. Plain English ("HELLO") goes through SAM's reciter. Prefix with / for SAM's phonemic alphabet ("/HEH4LOW") and skip the reciter.

pitch

Cell-note pitch. Cells 1..12 shift playback rate (chipmunk-style), NOT SAM's pitch param. This is what lets the render cache hit across cells.

cache

4 LRU slots keyed on (patch, sam_*, phrase, trim). Pattern loops with the same SAM voice never re-render after the first trigger - no timing drift.

pre-warm

Cache pre-warm. Editing any SAM knob (SOURCE / SPEED / PITCH / THROAT / MOUTH / TRIM) or committing a new PHRASE runs the render synchronously while you're still in the lab, so the next trigger after closing is an instant cache hit rather than a 30 ms cold-render block.

catch-up

Step catch-up. If a render does block the main loop past a step boundary, the missed step's notes still fire in order via a 16-slot catch-up queue -- so SAM patches never silently drop notes even at fast BPMs.

Settings overlay

open

SELECT in SONG focus.

X (in overlay)

Swap focused pane between SLOTS (left) and ACTIONS (right).

▲▼

Walk the focused pane's cursor.

A

Execute the selected action on the selected slot.

B / SELECT

Close the overlay.

Actions

NEW

Wipe the live project back to defaults. Saved slots are untouched. Overlay auto-closes back to the song screen so the blank arranger is the confirmation. Resets Y harmony overrides back to factory; keeps the global FM TUNE setting.

SAVE

Write the project to the focused slot's file on the SD card. Always prompts "SAVE- SLOT NN? A=yes B=no" so a wrong-cursor overwrite needs a deliberate second press. On success the overlay auto-closes back to the song screen; on failure ("SAVE FAILED") it stays open so the error is readable + retryable.

LOAD

Read the focused slot into the live project. Always prompts "LOAD SLOT NN? A=yes B=no" so an accidental A doesn't blow away unsaved work. Empty slots bail with "slot empty" before the prompt. On success the tracker flips to SONG focus and the overlay auto-closes; on failure ("LOAD FAILED") it stays open.

BPM

Hold A + Left/Right to set tempo (20..300).

MIDI

Tri-state MIDI mode toggle: OFF / SYNCIN / SYNCOUT. A + Left/Right cycles. SYNCIN slaves the DS clock to the mDS slot-2 MIDI cart; SYNCOUT drives a downstream slave from the DS.

OFFSET

Sync offset in ms (0..127). A + Left/Right nudges. Compensates the DS's near-zero-latency audio against a DAW softsynth's output buffer (typically 3-10 ms).

RATE

MIDI sync rate: 0.5x / 1x / 2x. A + Left/Right cycles.

FMTUNE

Global FM fine-tune in cents (-100..+100). A + Left/Right nudges. Calibration knob for the perceptual "FM sounds slightly off vs PSG" offset - not stored per project, lives like BPM. Applies to both F1 and F2.

Y harmony

Per-project Y / Y+U / Y+D / Y+L / Y+R overrides - five rows, each a signed semitone value (-36..+36). A + Left/Right nudges by 1 semitone. Defaults: +12 / +24 / -12 / -5 / +7 (the values main.c used to hardcode). Tailor harmony per groove; persists in the save file.

CLOSE

Same as B.

Randomize modal

Open with A+SELECT in PATTERN focus + EDIT. Notes only; insts never touched.

▲▼

Cycle MODE: sparse / dense / euclid / mutate.

◀►

Adjust DENSITY by 5% (clamped 0..100).

SELECT (in modal)

Toggle SCOPE between row (cursor voice) and pat (all 9 voices).

A

Roll + apply. Modal stays open so you can mash for new variations.

B

Close (last roll stays).

Modes

sparse

Clear row, then drop a uniform 1..12 note at each step with the density % chance.

dense

Every step gets a fresh uniform 1..12 note (density ignored).

euclid

N = round(density × 16 / 100), clamped 1..16. N notes Bresenham-spaced. Pitch = first existing non-rest in the row (else 1).

mutate

Walk existing notes; with density % chance, swap each to a DIFFERENT random 1..12. RESTs / X / S untouched.

Copy & paste

Row clipboard (per-voice)

R

Copy the cursor's voice row (16 notes + insts) to the clipboard. Status flashes row P2 (p05) -> CLIP.

A+R

Paste the clipboard onto the cursor's voice row, in whatever pattern is currently being edited. Cross-pattern paste works.

Pattern-wide (COPY FROM)

SELECT

Opens the COPY FROM modal in PATTERN focus.

▲▼

Walk the source pattern index.

A

Copy the source pattern's notes + insts onto the current edit pattern.

B / SELECT

Cancel.

Glitch performance FX

Enter with L. Hold a button while playing. All glitches are momentary - released drops the FX immediately.

Plain D-pad (no modifier):

◀

Loop 8 - beat-quantized 8-step block repeat (half-bar pin).

►

Loop 4 - 4-step block repeat (one-beat pin).

▲

Loop 2 - 2-step block repeat (half-beat pin).

▼

Half-time - each natural step plays for two song ticks.

X

Hold = stutter (32nd-note retrigger of the current step). Tap = focus toggle (still works in PERFORM so the visible playhead can follow).

START

Tap = play/pause. Hold = restart from song position 0. (Transport, not a glitch.)

Hold A + D-pad - pitch glitch:

A+▲

Momentary capo +12 semitones (octave up).

A+▼

Momentary capo -12 semitones (octave down).

A+◀

Tape slur DOWN - pitch slurs to a halt while held.

A+►

Tape slur UP - pitch bends up while held.

Hold B + D-pad - live arpeggios (fire on any patch):

B+▲

Arp up - octave staircase climbing.

B+▼

Arp down - octave staircase descending.

B+◀

Arp bounce (triangle).

B+►

Arp random.

Y Harmony - layered pitch shifts. Y's contribution sums with the A capo, so A+DOWN + Y+RIGHT = -12 + 7 = -5 (fourth down). The total caps at ±36 semitones.

Each Y combo's semitone value is per-project configurable from SETTINGS (rows Y, Y+U, Y+D, Y+L, Y+R). Factory defaults shown below.

Y

Held alone: default +12 semitones (octave up).

Y+▲

Default +24 semitones (two octaves up).

Y+▼

Default -12 semitones (octave down).

Y+◀

Default -5 semitones (fifth down).

Y+►

Default +7 semitones (fifth up).

FX-muted voices (see bottom-screen FX band) skip Y harmony, capo, tape slur, live arp, and stutter retrigger - they keep playing their pattern straight while the rest of the mix shifts around them.

External MIDI sync

cart

mDS slot-2 MIDI cart -- custom RP2040 in the GBA Slot-2. Writes magic STDS at 0x0A000000; DS confirms via the DETECT CART action in SETTINGS.

detection

Opt-in. Boot does NOT auto-probe -- raw slot-2 reads at boot wedge R4i and some emulator combos before first frame. Once you press DETECT CART in settings, the probe uses gbacartOpen() + 18-cycle SRAM wait timing to safely poll Slot-2; on a match the sync is active for the rest of the session.

sync_state

256-byte struct the Pico mirrors: tick_counter (24-PPQ), bpm_q8, flags (clock / transport), song_pos_16ths, micros.

poll rate

Every synth_tick (512 Hz). target_step = tick_counter / 6.

transport

DAW START (0xFA) snaps the song clock to the cart's target step and begins playing. STOP (0xFC) pauses.

local override

Y still works while the cart says stop, so you can rehearse offline.