Johnny Billquist wrote: Mine worked like any asynchronous serial interface. Plain RS-232. Sounds like there's a magic switch somewhere ... Now to find it. The Block/VT52 mode switch was in a switchpack on the bottom of the board, and was visible through the metal mesh that covered part of the bottom of the terminal. I dimly recall it was settable without taking anything apart by poking a paperclip through the mesh (powered off, natch). Leastways, that's how I recall it from circa 1977.... -- Lee K. Gleason N5ZMR Control-G Consultants lee.gleason at comcast.net