Programming a Duplex Computer System
This paper describes a method of duplex-computer
programming that has been used with two computers 
in a military defense system.  The method combines special
programs with a basic data processing program 
package.  The duplex operation gives the system greater
reliability.  After achieving the required level 
of integration, both computers do similar processing
on the same inputs and continually cross-check the 
intermediate and final results.
CACM November, 1961
Dow, J.
