Programs end up as numbers in mailboxes, also!
•Programs are stored the same way, as a buffer of numbers.  A program that reads someone’s last name and repeats it to them is compiled into a series of instructions that Norman understands.  Each instruction has a unique number.  For example,
–23 = “Copy the number from the next mailbox and hold that piece of paper in your left hand.” 
–188 = “Put the piece of paper in your left hand into the mailbox with the box number written on the piece of paper in your right hand.” 
•.