A video switching system wherein an integrated circuit designed to switch video signals responsive to a first type of signal is used to switch video signals of a second type of signal which is adapted to emulate the first type of signal. Circuitry for adapting the second type of signal to emulate the first type of signal is disclosed. A plurality of the adapted signals, where each would normally be coupled to their own IC input terminal, are couplable to a single S2 protocol terminal of the integrated circuit, through a single lead.