TVI 950 Keyboard Pinout

Does anyone have any references for the keyboard connector pinout on a Televideo 950 terminal? It's a 6p6c RJ-12 Connection. I'm guessing electrically it's similar to an AT or PS2 keyboard, with +5?, Ground, Data and Clock.

I'm guessing electrically it's similar to an AT or PS2 keyboard, with +5?, Ground, Data and Clock.

I think that's unlikely. 5V and Ground, yes, but I doubt it'll be anything like the IBM PS/2 protocol, because the TVI-950 pre-dates the IBM PC!