Indeed it isn't, but I had a go at the VT100
Technical Reference Guide
I found a reference to via
vt100.net, and more of it makes sense now,
Argh! I didn't realise there was a technical manual (in any case I
couldn't easily read it...).
I just grabbed the printest, fliped over the pages a few times and it
became reasonably clear to me. Now quite what that says about me is
another matter...
especially the combination clock and bidirectional
data line. That's
a lot of work for one wire. The 4-wire LK201 interface is much more
up my alley.
Indeed. That one is a fairly normal asynchronous serial interface at a
standard baud rate (I forget what).
I wonder why the VT100 interface was so odd. Maybe to get it onto a 3 pin
connecotr so they could use the 3-pole jack plugs (as we call them over
here). But there are 4, 5 and 6 pole versions that were used on UK (GPO)
telepohones years ago. Maybe those never crossed the Pond...
-tony