Phil - Although the tech is far beyond me (I'm scarcely beyond the rotary dial telephone), this is engagingly simple and sweet. ;D

A phone that will do just about anything, except make calls. I think someone has come out with a phone with numerals large enough that you can only push one at a time. I like my candlestick rotary. Already 30 years out of date when it was built in the 1970's.

The world's first public video telephone service was developed by Dr. Georg Schubert and opened by the German Reichspost in 1936 using square displays of 8 inches (20 cm), but which quickly closed in 1940 due to the WWII. In that service trial, video telephone lines linked Berlin to Nuremberg, Munich, and Hamburg, with terminals integrated within public telephone booths and transmitting at the same resolution as the first German TV sets, at 440 lines. The service was offered to the general public who had to simultaneously visit special post office videotelephone booths in their respective cities, but at the same time also had Nazi political and propagandistic overtones similar to the broadcasting of the 1936 Olympic Games in Berlin. The Deutsche Bundespost postal service would later develop and deploy its BIGFON (Broadband Integrated Glass-Fiber Optical Network) video telephony network from 1981 to 1988, serving several large German cities. Reichspost videphone: http://vsee.com/blog/wp-content/uploads/2011/06/1936ReichsPost1.jpg Reichspost also had a Zuse Z-4 computer in WW2: http://webfairy.org/missilegate/rfz/swaz/images/r-reich.of.the.black.sun_26.jpg

Thanks, everyone :-)

Seems almost everyone who's commented is thinking of "twin core" meaning the cables connecting the phone to the exchange..