Title: Module 7 Introduction
Course: CGS 1560 Microcomputer Operating Systems > Section: Module 7 - Input/Output Devices

There are four basic functions that make a computer system useful; input, processing, output and storage. It is the role of the operating system to manage all of these functions. The only thing that the end user sees is that the I/O operations have been performed without knowing all of the intricate details. You type on the keyboard and the characters appear on the screen. You don’t really care about all of processing that went into accomplishing that. Considering all of the combinations of hardware and software, this is a remarkable feat.

Device drivers act to translate requests to and from the various devices that may be connected to the computer. If an OS were designed that worked with all of the available devices and did not need device drivers, it would be too large to load on a personal computer. It is up to the device manufacturer to create the driver to work with a given OS. If you go to a manufacturer's website, you will find drivers for the various operating systems like Windows, Mac and Linux. Future hardware developments will likely free the OS of some of the hardware management tasks.

The hardware layer of the I/O architecture that supports input and output is called the chip set. The chip set drivers interface with the operating system with the chip set. The chip sets currently consist of a Northbridge and Southbridge integrated circuit set. The Northbridge is directly linked to the CPU with the Front Side Bus. It is the faster of the two chips and controls communication between the RAM, video and faster PCI-Express x 16. The second chip, the Southbridge, is not directly linked to the CPU and all communications must travel through the Northbridge to the CPU. The Southbridge handles all of the slower functions such as USB, SATA/PATA drives, PCI-Express x1, BIOS and other legacy functions.

Instructional Goal

The purpose of this module is to understand the relationship between input/output (I/O) devices and the operating system.

Module Objectives

Upon completion of this module, the student will be able to:

- Explain how input/output (I/O) devices work with the OS
- Describe the different I/O devices and there uses
- Select the most appropriate device driver
- Update and install one or more device drivers

Readings and Resources

- Textbook, Chapter 6