Apollo Abort Guidance System, also known as Abort Guidance Section, had instructions including ADD where the contents of memory location are added to an accumulator, and ADZ where the contents of memory are added to the same accumulator.
The Apollo Abort Guidance System (AGS, also known as Abort Guidance Section) was a backup computer system providing an abort capability in the event of failure of the Lunar Module's primary guidance system (Apollo PGNCS) during descent, ascent or rendezvous. ADD: The contents of memory location are added to Accumulator A. ADZ (Add and Zero): The contents of memory are added to Accumulator A. 
