Page 52 - UNI 101 Computer Science Handout.

Faculty of Nursing
Adult care Nursing Department

Chapter 3

3.1 Introduction

The typical personal computer system described in an advertisement consists of a CPU, memory, a DVD

or CD read-write drive, a hard disk drive, a keyboard, a mouse, wireless and wired network interfaces,
USB ports, sound and video system components, usually a modem, perhaps parallel, FireWire, and serial

ports, and a monitor. Additional available components include scanners of various types, printers,

plotters, TV tuners, floppy disk drives, and tape drives. Internal to the computer there is also a power

supply that converts wall plug power into voltages suitable for powering a computer. All the items

mentioned, except for the CPU, memory, and power supply, are considered peripheral (that is, external)
to the main processing function of the computer itself and are known, therefore, as peripherals. Some

of the peripherals use the USB, parallel, and serial ports as their interconnection point to the computer.

Others have their own interface to internal system buses that interconnect various parts of the
computer.

The peripherals in a large server or mainframe computer are similar, except larger, with more capacity.

Large numbers of hard disk drives may be grouped into arrays to provide capacities of tens or hundreds

of terabytes (TB). One or more high-speed network interfaces will be a major component. The capability
for handling large amounts of I/O will likely be a requirement. Means of implementing large-scale,

reliable backup will be necessary. Conversely, fancy displays, high-end graphics and audio cards, and

other multimedia facilities may be totally unneeded.

Despite different packaging and differences in details, the basic operations of these devices are similar,
regardless of the type of computer. In previous chapters we have already looked at the I/O operations

that control devices that are external to the CPU. Now we direct our attention to the operation of the

devices themselves. In this chapter we study the most important computer peripheral devices. We look

at the usage, important characteristics, basic physical layouts, and internal operations of each device.

We will also briefly consider the interface characteristics for these devices. Peripheral devices are
52 Academic Year 2025/2026