John holds a patent on a process on an electronic device to allow easier evaluation of critical paths within a complex project to be evaluated without resorting to the very expensive IBM-mainframe available at the time (early 60s).  Mainframe computer facilities were not an option for most project teams at the time. 

He invented a machine dedicated to quickly evaluating project activities "float", "lag" and other critical path evaluations for complex projects.  It was patented, and the device was built under contract by the federal government.  (Shown below).

The removable patch board representing a project's task relationships provided a means to evaluate different projects interchangeably with one computer.  The patch board was the "programming".

(click pictures for larger version)

U.S. Patent 3,289,323  ---- Patent information: