Owen R. Mock

One of the programmers who developed the PACT series of compilers for the IBM 701 and helped install the first operating system ever in operation, Mock pioneered computer operating systems in the 1950s as part of a group at the Los Angeles division of North American Aviation (NAA). His group developed the PACT series of compilers for the IBM 701 computer in 1954, and in December 1955 installed in the IBM 701 the "North American 701 Monitor", which was the first operating system to be in operation.

General Motors Research (GMR) also had an IBM 701 and used the compilers developed by his group. When Robert L. Patrick at GMR designed a non-stop multi-user batch processing operating system for use on the next generation computer (IBM 704), Mock's group at NAA and George Ryckman's group at GMR joined forces to develop Robert Patrick's design for the IBM 704. This GM-NAA I/O software was the first operating system for the 704 and began production in 1956.

His publications included: Logical Organization of the PACT I Compiler, J. ACM, vol. 3, No. 4, pages 279–287 (October, 1956); and The Share 709 System: Input-Output Buffering, J. ACM, vol. 6, No. 2, pages 145–151, (April, 1959).