p technology used in various military and NASA flight programs)
and the Singer- Kearfott SKC-2000 (then a candidate for the B-1A
program). Both of these machines were judged to require
extensive modification before being considered adequate. To
understand the configuration and makeup of the Space Shuttle
avionics system, it is necessary to understand the technological
environment of the early seventies. In the approximately 16
years since the inception of the system, computers and the
associated technology have undergone four generations of change.
If the system designers were operating in today's environment, a
much different set of design choices and options would be
available and, quite possibly, a different configuration would
have resulted. This section is intended to familiarize the
reader with the designer's world during the formative stages of
the system, with the technology available, and with the pressure
of factors other than technology which influenced the result.
Although the state of technology