Somewhat off topic, but if you want to make a 1920's VDU this might be for you!

[nige the hippy]

http://www.retronaut.co/2012/08/how-to-make-a-simple-television-1928/

 

[Trixter]

I'm lucky enough to have seen "mechanical" television in action at a museum demonstration two decades ago. It was definitely inferior to what was eventually adopted. Be thankful we aren't servicing the spinning metal discs inside our televisions and monitors...