earliest graphics display system in your collection?

I have a early/mid 1950s Mk 5 Mod 5 Target Designator System, made for the U S Navy. This device is a "normal" radar repeater (in laymans temrs - scope with the circular sweeping trace), but has four independent cursors under joystick control for designating targets for the gun crews. Essentially, if you wanted to blast someone, you took your joystick (assigned to one of the gun directors) and moved your cursor over the victim. The cursor is a half circle with a dot. Push the button on the joystick, and the signal is sent to the director and its computer. The director responds by drawing another half circle (not dot, and the other 180 degree arc), and moves it so it joins your cursor. Whe you see your half circle had turned into a full circle, the hot metal starts flying. The Mk 5 supports four joysticks for four directors, so four targets could be engaged independently using a time shared system. It consists of the repeater with the joysticks, a video generator cabinet with a zillion tubes, and a coordinate convertor cabinet with more tubes and lots of synchros and mechanical bits to do all the polar to XY conversion. William Donzelli aw288 at osfn.org