Segment 22280: Signal Multiplexer

Segment 22280: Signal Multiplexer is the fifth segment of the TIS-100.
==Module Information==
The Signal Multiplexer Segment is meant to select between IN.A, IN.B, and IN.A + IN.B for the segment output. (A multiplexer is a device that selects between several signals and forwards the selected input to a single output.)
Selection is performed by a third input, IN.S.
If IN.S is -1, IN.A should be output.
If IN.S is 1, IN.B should be output.
If IN.s is 0, IN.A + IN.B should be output.
==Gameplay Information==
!!WARNING!! The following section may contain spoilers for the game. Read at your own risk!!!
This is effectively meant to be the fifth puzzle. This puzzle will further teach the player how to write conditional statements and is one of the earliest moments where multicore processing may pay off.