| 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)
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.
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
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.
Assigning a Sample to a Pad
To assign slot 74 to Group D, Pad 8 (node 9502):
- METADATA SET on node
9500: {"active":9502} — select the active pad
- 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.
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
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.
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) |
Source Files
PROTOCOL.md — pad mapping formula, metadata fieldsdocs/protocol-evidence.md — capture-based evidencecaptures/sniffer-padmap-*.jsonl — raw capture data
