The six Program Flags act as convenient program switches. They are used
to indicate separate states of a program. The program can set, clear, or
sense the individual flip-flops. The program can also sense or make the
state "All Flags ZERO." They can also be used to synchronize various
input devices which occur at random times (see Input-Output, Typewriter
Input).
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Three toggle switch registers are connected to the Central Processor
(see Manual Controls).