This is not like the famed Quantel Paintbox, but (i believe) rather a hardware device for basic transitions, fades, wipes and maybe chroma keying, pan & zoom etc. I also understand it can be used for format conversion, ie NTSC to PAL etc.
CEL Electronics P152-B Universal Touch Screen Controller
This is the controller of the system, although it appears to be rack mountable i dont believe thats how it would have been installed. From an ergonomics point of view i think this would be installed face up in a video editing desk to allow easy use of the faders and the joystick. My assumption is you can create an effects program here which is processed by the P164 unit.
The P152 appears to be generic in nature and probably was a controller for several different systems, the legend on the front only gives basic ideas of the functions. On power up it tries to read the floppy disk and reports no disk found so i would expect a program for each of the processing units this can operate can be loaded in as needed.
The so-called touch screen is a simple IR emitter / receiver matrix over the green screen CRT, placing your finger on a 'button' would break two beams indicating your finger location. Primitive but i am sure it works!
On the front panel we have menu buttons VTR, FX, MIX, SEQ, SET UP & U. Visibly the 'FX' button has been used the most. Below that we have Take; Go & Stop then a Spinwheel which is a nicely damped 360 degree rotational encoder. Finally on this side we have 8 function keys relating to menus shown on the CRT.