© Thomas Kunz 2000
SCE 574
170
The Monitor
äMonitor reads jobs one at a time from the
input device
äMonitor places a job in the user program area
äA monitor instruction branches to the start of
the user program
äExecution of user pgm continues until:
äend-of-pgm
occurs
äerror
occurs
äCauses the CPU to fetch its next instruction
from Monitor
äOS:
äAlternates
execution between user program and the monitor program
äRelies on available hardware to effectively
alternate execution from various parts of memory
