IBM Series/1 (Computer)

As the Series/1 is used in more complex, unattended, or critical applications,
users of the product cannot tolerate the mean time to repair of the
current field service support. Long waits for technicians to arrive,
troubleshoot the system, and repair or replace parts are no longer acceptable.
This thesis presents the system architecture and functional capabilities
of a maintenance processor for the Series/1. The maintenance
processor designed herein can be used as the focal point of most system
support activities. This approach has been used in mainframe systems for
some time but has not, in the past, been deemed feasible for smaller systerns
such as the Series/1. This effort demonstrates the feasibility of a
maintenance processor in such systems, resulting in a simplification of
hardware and software while providing a significant improvement in total
system reliability, availability, and serviceability.

This investigation consisted of analyzing the source code of
one of the IBM Series/1's operating systems, the Event
Driven Executive, and one of its Application Program
Products, the Multiple Terminal Monitor, for combinations of
existing hardware mnemonic instructions. Such instructions
could possibly be vertically migrated into new single
mnemonic hardware instructions, thus improving system
performance. Two pairs of instructions were found which
seem to be strong candidates for such vertical
migration. Many instructions available on the Series/1 were
not used in any of the modules examined. This suggests that
some hardware instructions could be eliminated.