CRT displays [was: computer graphics in the 1950s]

On Fri, 24 Oct 2008, der Mouse wrote: I've never seen such a tube in any equipment myself, but there is a very interesting (German) discussion on the RCA 3DP1 polar-coordinate tube: http://www.radiomuseum.org/forum/3dp1_3dp1_polarkoordinaten_roehre.html Nonetheless I recommend having a look at this link as there are great pictures from the tube including pinout, data and photos from a disassembled tube. This particular tube has four deflection plates as in an ordinary electrostatically deflected tube. You apply a sine/cosine voltage to the plates to create a circle. But additionally there's a needle at the center of the screen used for the polar deflection. Maybe there is more information in the patents 2328259 (Polar coordinate cathode-ray tube, 1943) and 2864033 (Polar coordinate tube, 1958), both found on freepatentsonline.com, but the site seems to be non-functional at the moment. Christian