BOSS GM-800 MIDI CC chart, NRPN and OSC map¶
The BOSS GM-800 MIDI implementation: 83 CC, each named, for Claude (MCP), SuperCollider or any OSC app.
| Device | BOSS GM-800 |
|---|---|
| Vendor | BOSS |
| OSC prefix | /gm_800 |
| 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/boss/gm_800.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/boss/gm_800.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 gm_800: ask “what can the BOSS GM-800 do?” and it reads this map with list_routes. See the MCP guide.
MIDI CC and NRPN parameters (83)¶
| OSC address | CC | NRPN (MSB/LSB) | Range | Nature | Section |
|---|---|---|---|---|---|
/gm_800/performance/bank_select |
0 / 32 | 0–16383 | continuous | Performance | |
/gm_800/performance/modulation |
1 | 0–127 | continuous | Performance | |
/gm_800/performance/volume |
7 | 0–127 | continuous | Performance | |
/gm_800/performance/pan |
10 | 0–127 | continuous | Performance | |
/gm_800/performance/expression |
11 | 0–127 | continuous | Performance | |
/gm_800/performance/portamento_control |
84 | 0–127 | continuous | Performance | |
/gm_800/pedals/hold_1 |
64 | 0–127 | continuous | Pedals | |
/gm_800/pedals/sostenuto |
66 | 0–127 | continuous | Pedals | |
/gm_800/pedals/soft_pedal |
67 | 0–127 | continuous | Pedals | |
/gm_800/pedals/legato_foot_switch |
68 | 0–127 | continuous | Pedals | |
/gm_800/filter/cutoff |
74 | 0–127 | continuous | Filter | |
/gm_800/filter/resonance |
71 | 0–127 | continuous | Filter | |
/gm_800/envelope/attack_time |
73 | 0–127 | continuous | Envelope | |
/gm_800/envelope/decay_time |
75 | 0–127 | continuous | Envelope | |
/gm_800/envelope/release_time |
72 | 0–127 | continuous | Envelope | |
/gm_800/vibrato/rate |
76 | 0–127 | continuous | Vibrato | |
/gm_800/vibrato/depth |
77 | 0–127 | continuous | Vibrato | |
/gm_800/vibrato/delay |
78 | 0–127 | continuous | Vibrato | |
/gm_800/effects/reverb_send_level |
91 | 0–127 | continuous | Effects | |
/gm_800/effects/chorus_send_level |
93 | 0–127 | continuous | Effects | |
/gm_800/assignable_parameters/assignable_parameter_01 |
1 | 0–127 | continuous | Assignable parameters | |
/gm_800/assignable_parameters/assignable_parameter_02 |
2 | 0–127 | continuous | Assignable parameters | |
/gm_800/assignable_parameters/assignable_parameter_03 |
3 | 0–127 | continuous | Assignable parameters | |
/gm_800/assignable_parameters/assignable_parameter_04 |
4 | 0–127 | continuous | Assignable parameters | |
/gm_800/assignable_parameters/assignable_parameter_05 |
5 | 0–127 | continuous | Assignable parameters | |
/gm_800/assignable_parameters/assignable_parameter_06 |
6 | 0–127 | continuous | Assignable parameters | |
/gm_800/assignable_parameters/assignable_parameter_07 |
7 | 0–127 | continuous | Assignable parameters | |
/gm_800/assignable_parameters/assignable_parameter_08 |
8 | 0–127 | continuous | Assignable parameters | |
/gm_800/assignable_parameters/assignable_parameter_09 |
9 | 0–127 | continuous | Assignable parameters | |
/gm_800/assignable_parameters/assignable_parameter_10 |
10 | 0–127 | continuous | Assignable parameters | |
/gm_800/assignable_parameters/assignable_parameter_11 |
11 | 0–127 | continuous | Assignable parameters | |
/gm_800/assignable_parameters/assignable_parameter_12 |
12 | 0–127 | continuous | Assignable parameters | |
/gm_800/assignable_parameters/assignable_parameter_13 |
13 | 0–127 | continuous | Assignable parameters | |
/gm_800/assignable_parameters/assignable_parameter_14 |
14 | 0–127 | continuous | Assignable parameters | |
/gm_800/assignable_parameters/assignable_parameter_15 |
15 | 0–127 | continuous | Assignable parameters | |
/gm_800/assignable_parameters/assignable_parameter_16 |
16 | 0–127 | continuous | Assignable parameters | |
/gm_800/assignable_parameters/assignable_parameter_17 |
17 | 0–127 | continuous | Assignable parameters | |
/gm_800/assignable_parameters/assignable_parameter_18 |
18 | 0–127 | continuous | Assignable parameters | |
/gm_800/assignable_parameters/assignable_parameter_19 |
19 | 0–127 | continuous | Assignable parameters | |
/gm_800/assignable_parameters/assignable_parameter_20 |
20 | 0–127 | continuous | Assignable parameters | |
/gm_800/assignable_parameters/assignable_parameter_21 |
21 | 0–127 | continuous | Assignable parameters | |
/gm_800/assignable_parameters/assignable_parameter_22 |
22 | 0–127 | continuous | Assignable parameters | |
/gm_800/assignable_parameters/assignable_parameter_23 |
23 | 0–127 | continuous | Assignable parameters | |
/gm_800/assignable_parameters/assignable_parameter_24 |
24 | 0–127 | continuous | Assignable parameters | |
/gm_800/assignable_parameters/assignable_parameter_25 |
25 | 0–127 | continuous | Assignable parameters | |
/gm_800/assignable_parameters/assignable_parameter_26 |
26 | 0–127 | continuous | Assignable parameters | |
/gm_800/assignable_parameters/assignable_parameter_27 |
27 | 0–127 | continuous | Assignable parameters | |
/gm_800/assignable_parameters/assignable_parameter_28 |
28 | 0–127 | continuous | Assignable parameters | |
/gm_800/assignable_parameters/assignable_parameter_29 |
29 | 0–127 | continuous | Assignable parameters | |
/gm_800/assignable_parameters/assignable_parameter_30 |
30 | 0–127 | continuous | Assignable parameters | |
/gm_800/assignable_parameters/assignable_parameter_31 |
31 | 0–127 | continuous | Assignable parameters | |
/gm_800/assignable_parameters/assignable_parameter_64 |
64 | 0–127 | continuous | Assignable parameters | |
/gm_800/assignable_parameters/assignable_parameter_65 |
65 | 0–127 | continuous | Assignable parameters | |
/gm_800/assignable_parameters/assignable_parameter_66 |
66 | 0–127 | continuous | Assignable parameters | |
/gm_800/assignable_parameters/assignable_parameter_67 |
67 | 0–127 | continuous | Assignable parameters | |
/gm_800/assignable_parameters/assignable_parameter_68 |
68 | 0–127 | continuous | Assignable parameters | |
/gm_800/assignable_parameters/assignable_parameter_69 |
69 | 0–127 | continuous | Assignable parameters | |
/gm_800/assignable_parameters/assignable_parameter_70 |
70 | 0–127 | continuous | Assignable parameters | |
/gm_800/assignable_parameters/assignable_parameter_71 |
71 | 0–127 | continuous | Assignable parameters | |
/gm_800/assignable_parameters/assignable_parameter_72 |
72 | 0–127 | continuous | Assignable parameters | |
/gm_800/assignable_parameters/assignable_parameter_73 |
73 | 0–127 | continuous | Assignable parameters | |
/gm_800/assignable_parameters/assignable_parameter_74 |
74 | 0–127 | continuous | Assignable parameters | |
/gm_800/assignable_parameters/assignable_parameter_75 |
75 | 0–127 | continuous | Assignable parameters | |
/gm_800/assignable_parameters/assignable_parameter_76 |
76 | 0–127 | continuous | Assignable parameters | |
/gm_800/assignable_parameters/assignable_parameter_77 |
77 | 0–127 | continuous | Assignable parameters | |
/gm_800/assignable_parameters/assignable_parameter_78 |
78 | 0–127 | continuous | Assignable parameters | |
/gm_800/assignable_parameters/assignable_parameter_79 |
79 | 0–127 | continuous | Assignable parameters | |
/gm_800/assignable_parameters/assignable_parameter_80 |
80 | 0–127 | continuous | Assignable parameters | |
/gm_800/assignable_parameters/assignable_parameter_81 |
81 | 0–127 | continuous | Assignable parameters | |
/gm_800/assignable_parameters/assignable_parameter_82 |
82 | 0–127 | continuous | Assignable parameters | |
/gm_800/assignable_parameters/assignable_parameter_83 |
83 | 0–127 | continuous | Assignable parameters | |
/gm_800/assignable_parameters/assignable_parameter_84 |
84 | 0–127 | continuous | Assignable parameters | |
/gm_800/assignable_parameters/assignable_parameter_85 |
85 | 0–127 | continuous | Assignable parameters | |
/gm_800/assignable_parameters/assignable_parameter_86 |
86 | 0–127 | continuous | Assignable parameters | |
/gm_800/assignable_parameters/assignable_parameter_87 |
87 | 0–127 | continuous | Assignable parameters | |
/gm_800/assignable_parameters/assignable_parameter_88 |
88 | 0–127 | continuous | Assignable parameters | |
/gm_800/assignable_parameters/assignable_parameter_89 |
89 | 0–127 | continuous | Assignable parameters | |
/gm_800/assignable_parameters/assignable_parameter_90 |
90 | 0–127 | continuous | Assignable parameters | |
/gm_800/assignable_parameters/assignable_parameter_91 |
91 | 0–127 | continuous | Assignable parameters | |
/gm_800/assignable_parameters/assignable_parameter_92 |
92 | 0–127 | continuous | Assignable parameters | |
/gm_800/assignable_parameters/assignable_parameter_93 |
93 | 0–127 | continuous | Assignable parameters | |
/gm_800/assignable_parameters/assignable_parameter_94 |
94 | 0–127 | continuous | Assignable parameters | |
/gm_800/assignable_parameters/assignable_parameter_95 |
95 | 0–127 | continuous | Assignable parameters |
Performance MIDI¶
Notes, pitch bend and any CC are also available: /gm_800/note/on <note> <velocity>, /gm_800/cc/<number> <value>, /gm_800/pitchbend <0-16383>, /gm_800/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.
Frequently asked questions¶
Which MIDI CC controls the filter cutoff on the BOSS GM-800?
CC 74 (0–127), named /gm_800/filter/cutoff in SynthHub's map.
How many parameters of the BOSS GM-800 can be controlled over MIDI?
SynthHub's map of the BOSS GM-800 lists 83 MIDI CC parameters, each with its number, range and a readable name; the full chart is on this page.
Can an AI agent like Claude control the BOSS GM-800?
Yes: SynthHub's hosted MCP server knows the BOSS GM-800's MIDI map, and its browser relay lets the agent send it parameter changes or load a sound, each sound change confirmed by you.