ep133-device

name	ep133-device
description	Use when reasoning about EP-133 KO-II device organization: slot/bank layout, where samples live, how pads map to filesystem nodes, node ID system, or project structure. Does NOT cover SysEx wire format — see ep133-protocol for that.

EP-133 KO-II Device Organization

Hardware Facts

• Sample slots: 999 (numbered 1–999, global across all projects)
• Projects: Up to 16 reported (P01–P16). Formula and pad_mapping.py only verified for projects 1–9. Projects 10–16 may use a different node encoding — treat as open question.
• Memory: ~128 MB total
• Audio: 16-bit WAV; 46,875 Hz confirmed; 44,100 Hz also reported to work (open question)
• Physical pads: 12 per bank (labeled 0–9, ., Enter)

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Slot / Bank Layout

Bank 0 has 99 slots (1–99); banks 1–9 have 100 slots each. Total = 999.

Bank	Slots	Label
0	001–099	KICK
1	100–199	SNARE
2	200–299	CYMB
3	300–399	PERC
4	400–499	BASS
5	500–599	MELOD
6	600–699	LOOP
7	700–799	USER 1
8	800–899	USER 2
9	900–999	SFX

Slots are global — they represent audio data in device memory and do not belong to any project.

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Two Addressing Systems: Slots vs Nodes

The device uses two separate ID spaces:

Slot IDs (1–999)

• Audio data locations
• Used for upload, download, delete
• ko2 info <slot>, ko2 get <slot>, ko2 put <file> <slot>

Filesystem Node IDs

• Internal filesystem objects: directories, pad assignments, project containers
• Key fixed nodes:
  • 1000 — /sounds/ root directory (parent node for all uploads)
  • 2000+ — Project and pad hierarchy

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Node ID Formula for Pad Nodes

node_id = 2000
        + (project_num × 1000)   # project layer
        + 100                     # groups-container layer (always present)
        + group_offset            # A=100, B=200, C=300, D=400
        + pad_file_num            # physical pad → filesystem file number

The +100 mid-formula is a fixed intermediate node (the groups container) that sits between the project node and the group node. It is not optional.

Verified for projects 1–9 only (pad_mapping.py raises ValueError for project > 9).

Pad → pad_file_num mapping

Physical pads are numbered bottom-to-top on the device; filesystem stores them top-to-bottom:

Physical layout:     Filesystem file_num:
  10  11  12  (top)    01  02  03
   7   8   9           04  05  06
   4   5   6           07  08  09
   1   2   3  (bot)    10  11  12

Pad labels map to physical positions: 7=pad 1, 8=pad 2, 9=pad 3, 4=pad 4, … 0=pad 10, .=pad 11, Enter=pad 12.

Example: Project 1, Group A, Pad label 1 (physical 11, file_num=2): 2000 + 1×1000 + 100 + 100 + 2 = 3202

All four groups follow the same pattern with +100 offset per group. Group A fully confirmed from captures; B/C/D each confirmed at 2 data points — all consistent.

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Assigning a Sample to a Pad

To assign slot 74 to Group D, Pad 8 (node 9502):

1. METADATA SET on node 9500: {"active":9502} — select the active pad
2. METADATA SET on node 9502: {"sym":74} — assign slot 74 (sym = "slot assignment", needs confirmation)

To set trim points on the same pad:

• METADATA SET on node 9502: {"sample.start":2318,"sample.end":8006}

Anomaly: {"sym":807} observed on node 5407 — outside the 9500+ range. Suggests pad/sample assignments may also exist in other node ranges. Needs confirmation.

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Projects

• Numbered 1–16 (reported); 1–9 verified in formula/code
• Switch project via SysEx (device ID 0x7C): {"active":<project_num × 1000>}
  • Project 8 → {"active":8000}
• Each project has its own pad assignments (separate node ranges)
• Sample slots are shared across projects — same slot can be assigned to pads in multiple projects

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Backup File Format (.pak)

ZIP archive, contents observed:

backup.pak (ZIP)
├── meta.json          # Device info, firmware version, timestamp
├── projects/          # Project data (format of contents not fully documented)
└── sounds/            # All sample WAV files
    ├── 001 sample name.wav
    └── ...

Filename format: NNN name.wav (3-digit slot number + space + sample name).

Project-only backup: .ppak extension — internal format unknown.

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Metadata Fields on Sample Nodes

Observed on slot nodes via FileOp.METADATA GET/SET:

Field	Example	Notes
channels	1	Audio channels
samplerate	46875	Sample rate
sound.playmode	"oneshot"
sound.rootnote	60	MIDI note
sound.pitch	0
sound.pan	0
sound.amplitude	100
envelope.attack	0
envelope.release	255
time.mode	"off"
sound.loopstart	0	Optional
sound.loopend	<n>	Optional
sym	74	Slot assigned to pad node (needs confirmation)
sample.start	0	Trim start
sample.end	8006	Trim end
active	9502	Active child node (UI navigation)

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Source Files

• PROTOCOL.md — pad mapping formula, metadata fields
• docs/protocol-evidence.md — capture-based evidence
• captures/sniffer-padmap-*.jsonl — raw capture data