The Tektronix 155-0013-00 (M022) is a Tek-made horizontal chop and alt. binary integrated circuit in a TO-99 can, designed by Les Larson.
It receives horizontal mode switch information, alternating signals, and chopping signals (500 kHz), and produces an output to the horizontal switch as to which sweep should be received. This same output is used in the horizontal lockout logic and in both vertical alt. binaries.