Dennis M. Ritchie (March 1993). “The Development of the C Language”. ACM SIGPLAN Notices28 (3): 201–208. doi:10.1145/155360.155580. http://cm.bell-labs.com/cm/cs/who/dmr/chist.html. "People often guess that they were created to use the auto-increment and auto-decrement address modes provided by the DEC PDP-11 on which C and Unix first became popular. This is historically impossible, since there was no PDP-11 when B was developed. The PDP-7, however, did have a few `auto-increment' memory cells, with the property that an indirect memory reference through them incremented the cell. This feature probably suggested such operators to Thompson; the generalization to make them both prefix and postfix was his own. Indeed, the auto-increment cells were not used directly in implementation of the operators, and a stronger motivation for the innovation was probably his observation that the translation of ++x was smaller than that of x=x+1."
Dennis M. Ritchie (March 1993). “The Development of the C Language”. ACM SIGPLAN Notices28 (3): 201–208. doi:10.1145/155360.155580. http://cm.bell-labs.com/cm/cs/who/dmr/chist.html. "People often guess that they were created to use the auto-increment and auto-decrement address modes provided by the DEC PDP-11 on which C and Unix first became popular. This is historically impossible, since there was no PDP-11 when B was developed. The PDP-7, however, did have a few `auto-increment' memory cells, with the property that an indirect memory reference through them incremented the cell. This feature probably suggested such operators to Thompson; the generalization to make them both prefix and postfix was his own. Indeed, the auto-increment cells were not used directly in implementation of the operators, and a stronger motivation for the innovation was probably his observation that the translation of ++x was smaller than that of x=x+1."
