Question

a crucial element in the first step of computer - based gaming involved an electrical device similar to a radar screen called a(n) ______.
oscilloscope
controller
cathode
cartridge

Explanation:

An oscilloscope is an electrical device that can display signals graphically, similar to a radar screen. A controller is for input, a cathode is part of a vacuum tube, and a cartridge is for storage.

Answer:

oscilloscope