April 2019 firmware update instructions
1. Modify the wired and wireless WIN/MAC memory switch independently;
2. Solve the BUG caused by FN not releasing in M mode when FN moves the position and switches back to OFFICE;
3. Solve the BUG that the first character of USB cable computer is not output when it wakes up after energy saving sleep;
4. Solve the problem of fake death input in MAC wired mode;
5. Remove the enumerated programming keyboard channel, and switch to Win mode for programming and firmware upgrading under MAC (it will be cancelled later).