Segment 10981: Signal Amplifier

Segment 10981: Signal Amplifier is the second segment of the TIS-100. 
==Module Information==
The Signal Amplifier Segment is meant to double the input of a signal.
==Gameplay Information==
!!WARNING!! The following section may contain spoilers for the game. Read at your own risk!!!
This is effectively meant to be the second puzzle. The idea is to teach the player how to use the add command. In this case, it is also meant to showcase that the accumulator register can be a source operand for the add command. This is fairly typical in many computer architectures and might not take more proficient assembly programmers by surprise. It might catch people new to ASM by surprise though.