The anode collected or passed the beam, producing current variations in binary code, one bit at a time. CK1414 Character generator monoscope for text mode video rendering in early computer monitors, with a square target having letters, digits and symbols patterned on it in a customer-supplied 8x8 or 8x12 array. An electron beam selects and scans a character, both by appropriate deflection, and generates an analog video signal.[12][13] 7828 Scan conversion tube, an analog video standards transcoder consisting of a CRT/camera tube combination.