"But Rooman, Why have both RUN, and RUNKEE?" Joey asked in wide-eyed
wonderment.
    "Well, Joey, we can see that RUNKEE is called when the run key is pressed. 
But this only happens when we are not running a program so there is no runtime
information to save in the environment.  On the other hand RUN must be
executed from a program, calculator or otherwise.  This implies that the
environment must be saved as you switch from one program to another."
    Rooman, pleased that he had enlightened his youthful charge, sat back on
his bedroll looking off into the starry darkness of the desert sky.  Joey sat
with his knees tucked up against the chill and watched as the fire slowly
began to die.  The fire had turned to waves of red heat fanned through the
coals by the desert wind when Joey looked up.
    "Rooman.  Who was Wendy?"

                --excerpt from the HP-75 Internal Design Specification
                [They just don't write docs like they used to.  -jkh-]