GEM rp-x: MIDI CC, NRPN and OSC map¶
The GEM rp-x as named OSC addresses — 20 CC — ready to use from Claude (MCP), SuperCollider, Sonic Pi, TouchDesigner or any OSC app via osc-bridge.
| Device | GEM rp-x |
|---|---|
| Vendor | GEM |
| OSC prefix | /rp_x |
| Source | 📦 Derived from MIDI Guide (community CC/NRPN data) |
| Firmware | unknown |
| Revision | per pencilresearch canonical CSV |
| Upstream | pencilresearch |
| Data licence | CC-BY-SA-4.0 — MIDI Guide (https://midi.guide) by Pencil Research and contributors |
| Driver file | devices/gem/rp_x.json |
Not tested on the device yet
This driver comes from documentation or community data and has not been checked on real hardware. If you own one, a quick test and a pull request promoting it helps everyone — see CONTRIBUTING.
How do you control it?¶
Find the MIDI ports, then start the bridge with this driver:
osc-bridge detect # prints the ready-to-run line for what is plugged in
osc-bridge run --device devices/gem/rp_x.json --out-port <N> --in-port <M>
Then send OSC to 127.0.0.1:7777, for example:
From Claude or any MCP client, the osc-bridge mcp server exposes this driver as rp_x: ask “what can the GEM rp-x do?” and it reads this map with list_routes. See the MCP guide.
MIDI CC and NRPN parameters (20)¶
| OSC address | CC | NRPN (MSB/LSB) | Range | Nature | Section |
|---|---|---|---|---|---|
/rp_x/general/modulation |
1 | 0–127 | continuous | General | |
/rp_x/general/portamento_time |
5 | 0–127 | continuous | General | |
/rp_x/general/volume |
7 | 0–127 | continuous | General | |
/rp_x/general/pan_pot |
10 | 0–127 | continuous | General | |
/rp_x/general/expression |
11 | 0–127 | continuous | General | |
/rp_x/general/sustain |
64 | 0–127 | continuous | General | |
/rp_x/general/portamento |
65 | 0–127 | continuous | General | |
/rp_x/general/sostenuto |
66 | 0–127 | continuous | General | |
/rp_x/general/soft |
67 | 0–127 | continuous | General | |
/rp_x/filter/resonance |
71 | 0–127 | continuous | Filter | |
/rp_x/envelopes/release_time |
72 | 0–127 | continuous | Envelopes | |
/rp_x/envelopes/attack_time |
73 | 0–127 | continuous | Envelopes | |
/rp_x/filter/cut_off |
74 | 0–127 | continuous | Filter | |
/rp_x/envelopes/decay_time |
75 | 0–127 | continuous | Envelopes | |
/rp_x/general/vibrato_rate |
76 | 0–127 | continuous | General | |
/rp_x/general/vibrato_depth |
77 | 0–127 | continuous | General | |
/rp_x/general/vibrato_delay |
78 | 0–127 | continuous | General | |
/rp_x/general/portamento_control |
84 | 0–127 | continuous | General | |
/rp_x/fx/reverb_send_level |
91 | 0–127 | continuous | FX | |
/rp_x/fx/chorus_send_level |
93 | 0–127 | continuous | FX |
Performance MIDI¶
Notes, pitch bend and any CC are also available: /rp_x/note/on <note> <velocity>, /rp_x/cc/<number> <value>, /rp_x/pitchbend <0-16383>, /rp_x/program_change <n>.
Limitations¶
CC/NRPN only. SysEx (preset management, display control, bulk dump/load, vendor-proprietary opcodes) is NOT covered by pencilresearch. To extend this device with SysEx, sniff the vendor editor, add `sysex.header/footer` + `commands` blocks, and use `update_device.md` PR template.