IBM System/360 Operating Guide

Running State. In the running or operating state,
the CPU executes instructions (if not waiting) and
interruptions (if not masked off).
Status. System states are defined as: problem/
supervisor, wait/running, masked/interruptable,
and stopped/operating.
Stopped State. See Manual State.
Supervisor Program. A control routine, which is
executed in the supervisor state, that performs
the following functions: .
Controls input/output operations.
Coordinates system resources.
Maintains the flow of operations through the CPU.
Acts in response to requirements for altering
or interrupting the flow of operations.
Supervisor State. All instructions are valid. PSW-
bit 15 is off.
Tag. Symbols that give information about an I/O
operation.
Trap. A change in microprogramming that is
automatically initiated by some machine condition.
UCW. See Auxiliary Storage.
Wait State. In the wait state (wait light on), no
instructions are processed. Bit 14 of the PSW is
on. The CPU clock continues to run, however, and
interruptions are executed unless masked off.
45

IBM System/360 Specifications

General

Brand	IBM
Model	System/360
Category	Desktop
Language	English