Comment by rswail

This reminds me of Mel:

    Mel's job was to re-write
    the blackjack program for the RPC-4000.
    (Port?  What does that mean?)
    The new computer had a one-plus-one
    addressing scheme,
    in which each machine instruction,
    in addition to the operation code
    and the address of the needed operand,
    had a second address that indicated where, on the revolving drum,
    the next instruction was located.

https://users.cs.utah.edu/~elb/folklore/mel.html