FT-4 lacks "channel" support to programmable keys
The programmable keys for the FT-4 and FT-65 can each be programmed for any of 3 functions. This is not obvious from the manual but is clear from the Yaesu software. The code only implements "mode shortcut" and "mem shortcut". It lacks the "channel" function. The "channel" function is a separate special mem for each programmable key.