Weird CRT needed

[jr_tech]

Was the crt a "roundie" like in this console ?
Some of these consoles may have used a type of "Charactron" CRT, where the beam first is deflected to plate that is like a stencil for typically, 64 alpha-numeric characters. Then the beam (now with the shape of the desired character) is re-centered in the electron gun by another deflection system, and then it is deflected to the screen by yet another deflection system. These guns were very long, because of the complex deflection scheme and the character mask.

http://en.wikipedia.org/wiki/Charactron

P31 would be a Blue-Green phosphor.

jr