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z/Architecture – Processing Workloads 2.5


5 hours



The z/OS Architecture – Processing Workloads course describes how today’s z/OS system processes workloads, focusing on the concepts of address spaces showing how they provide the environment under which tasks can run. You will look at the different types of CPUs that can be configured in a z/OS system and see how programs issue instructions to the CPU. Diving down deeper you will then look at the CPU chips themselves and view the components that comprise them, looking at their involvement in processing work. Finally, the major components that comprise the mainframe’s I/O structure are presented to show how work moves throughout the z/OS environment.


Operations, Systems Programmers, and technical support personnel requiring in-depth knowledge about how tasks are processed within a z/OS environment.


Completion of the z/OS – Concepts course, or equivalent knowledge.


After completing this course, the student will be able to describe how:

  • Address spaces are used as containers for units of work
  • The CPU processes instructions
  • CPU sharing is used and managed
  • The Channel Subsystem facilitates I/O

Course Content

Address Spaces and Tasks

Address Space Structure and Purpose
Accessing and Sharing Memory
Address Space Control Blocks
System and Subsystem Address Spaces
Starting and Stopping Address Spaces
Dispatchable Units of Work
Task Activity Within an Address Space
Task Control Blocks
Service Request Blocks

Processors and CPUs

Program Instructions
Loading a Program into Memory
Types of Registers
Program Status Word
Prefixed Save Area
Single Chip Modules
CPU Types
Instruction and Data Caching
Simultaneous Threading

Sharing the CPU

CPU Sharing Concepts
Obtaining and Releasing CPU Resources
Selecting CPU Work
Processing work on zIIPs
Interrupt Processing
Interrupt Handlers

I/O and the Channel Subsystem

Traditional I/O Processing
z/OS Channel Subsystem
Logical Channel Subsystems
Control Units and Devices
I/O Definitions
I/O Process
Access Methods
Parallel Access Volumes

z/Architecture – Processing Workloads 2.5 Mastery Test