I don’t know how much interest there is in this, but I’ve put a ChannelF core up on github.
It would be nice if it could be moved to libretro at some point, though I’m not sure what this would involve. @markwkidd handled all of that for FreeIntv, so I’m a bit in the dark.
Anyhow, it looks to be “complete”. All of the games work, as far as I can tell, and there are no obvious bugs.
Like the keypad on my intellivision core , there’s an “overlay” for the console controls. You can switch between the controller and the console controls by pressing ‘start’.
I’ve considered automatically switching back to the controller once a console button is pressed. It’s convenient when you’re selecting game options, but once you hit the ‘start’ console button, it’s a race to hit start to get to the game. All opinions on this are welcome.