Xerox Sigma 6 Reference Manual page 15

This multiple capabi lity makes SIGMA 6 particularly effec-
tiv.", for multiuse applications. The major SIGMA 6 multiuse
computer features are:
Priority Interrupt. In a multiuse environment, many ele-
ments operate asynchronously. Thus, a true pri ority i n-
terrupt system is essential. It allows the computer system
to respond quickly {and in proper order} to the many de-
mands made on it, without the high overhead cost of
compl icated programming, lengthy execution time, and
extensive storage allocations.
Quick Response. The many features that combine to pro-
duce a quick-response system - multiple register blocks,
quick context saving, push-pull operations - benefit all
users because more of the computer's resources are avail-
able for useful work.
Memory Protection. The memory protection features protect
each user from every other user and also guarantee the
integrity of programs that are essential to critical real-time
applications.
Input/Output. Because of its wide range of capacities
and speeds (with and without channels), the SIGMA 6
I/O system simultaneously satisfies the needs of many
different application areas economically, both in terms of
equipment and of programming.
Instruction Set. The large SIGMA 6 instruction set pro-
vides the computational and data-handling capabilities
required for widely differing application areas; therefore,
each user's program length (thus running time) is decreased
and the speed of obtaining results is increased.
Multiuse Features 7