Gandalf

De writes: I always thought they got lumped into "short haul 4-wire modems". They do have "DCD" lights on the front. I seem to recall that it's just a light and doesn't actually assert any RS-232 pins. But they could just be differential line drivers probably with isolation. 20+ years ago I'm sure I looked inside to see what's in there but I can't recall. I always thought they did some simplistic and almost certainly not Bell-standard FSK or PSK but that was just my impression, no actual evidence to back that up. Did the 4-wire screws on the back have labels of "+" and "-"? That would be a point in favor of them being line drivers and not modems (although some simple modems were in fact phase-sensitive). We used them between serial concentrators on different floors or between serial concentrators between nearby buildings. I note that there's no Gandalf directory at bitsavers. Gandalf certainly has a unique heritage not really being a "computer" company in the usual sense but for so many of us it was the gateway from terminal to the computer or between computers. I get the impression they were far more common at large academic institutions than at any commercial site. Tim.