RedThunder_K75_Ultra keyboard software
sharkfin is a free, open-source replacement for the RedThunder_K75_Ultra app: remap keys, set the RGB, paint per-key colour and record macros on 2 RedThunder_K75_Ultra boards, 2 of which accept changes. Use it in a Chromium browser with nothing to install, or as an app on Windows, macOS and Linux. It runs entirely on your own machine, with no account.
Does sharkfin support my RedThunder_K75_Ultra board?
The table lists every RedThunder_K75_Ultra model sharkfin knows, 2 in all. If yours is missing, plug it in anyway: these boards report their own device id, and sharkfin identifies anything built on ROYUAN hardware from that reply, works out which command set it speaks, and asks before it writes.
| Board | Writable | Layout |
|---|---|---|
| K75 Ultra UK | yes | after a one-time check |
| K75 Ultra US | yes | after a one-time check |
"Writable" means sharkfin will change settings on it. Read-only boards are ones whose command set is not established yet; sharkfin identifies them and reads from them, but refuses to write, because the two protocol families in this hardware share opcodes that mean different things. "After a one-time check" means the picture exists but is confirmed against your own board first: two boards can share one picture and still disagree about which internal slot a key lives in, so sharkfin trusts the keyboard over its own files.