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Types of Computers and

Computer Systems

Objectives

• You will be able to:– Define what is a computer– Differentiate between the different types of

computers– Explain the concept of Computer Systems – Demonstrate the concepts of: architecture,

specification, data, and processing– Define the concept of motherboard and mention the

main components of it (CPU, cards)– Differentiate between input and output functions and

devices.

What is a Computers?

• A computer: is an electronic device that:– Accepts information and instructions from

users– Manipulates the information according to the

instructions– Displays the information in some way– And Stores the information for retrieval later.

• Computers are classified by: size, speed and capabilities

Types of Computers?

1. Personal Computers

2. Hand-held Computers

3. Mainframe Computers

4. SupercomputersNote: Xbox and PlayStation are also computers

Personal Computers:

• Personal Computers: used by a single user for use in home or office. They are used for general computing tasks such as:

– Word processing– Manipulating numbers– Working with photographs or graphics– Exchanging email and accessing the Net

Personal Computers Examples:

• Desktop computer (designed to set compactly on a desk):

– Notebook (laptop): small and lightweight and designed for portability

– Tablet PC: designed for compatibility and includes the capability of recognizing ordinary handwriting on the screen

• Notebook is more expensive than Desktop, and Tablet PC is more expensive than notebook computers

Handheld Computers

• Handheld Computers: are small computers that fit in the palm of your hand with more limited capabilities than personal computers:

– PDA (Personal Digital Assistants): are used to maintain an electronic appointment book, address book, calculator, and notepad

• High-end PDA: All-in-one devices that can send and receive emails and make phone calls (e.g. iPhone)

– MP3 players: are used to store and play music (some models can play digital movies and television shows)

– Cell Phone: are used to make phone calls, store contact information, take and store digital photos, play video, store music. Built-in calculator. High-end cell phones can perform many of the same functions as PDA

Mainframe Computers

• Mainframe Computers: are used by larger business and government agencies to provide centralized storage, processing, and management of large amounts of data

• Its price varies from several hundred thousand dollars to several million dollars

Supercomputers

• Supercomputers: are the fastest and largest computers used by large corporations and government agencies when the tremendous volume of data would seriously delay processing on a mainframe computer.

• It could cost tens of millions dollars

Understanding Terminals

• When using mainframes or supercomputers each user inputs processing request and views output through a terminal or terminal emulator.

• Terminal: has a keyboard for input and a monitor for output, but process little or no data on its own.

• Terminal Emulator: a personal computer, workstation, or server that uses special software to imitate a terminal so that the PC can communicate with the mainframe or supercomputer for complex data processing.

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Computer System

• Computer System: includes computer Hardware and Software

• Hardware: the physical components of a computer

• Software: the intangible components of a computer system; the programs or the list of instructions that the computer needs to perform a specific task

Architecture and Specifications

• Architecture - Configuration: the design and construction of a computer

• Specification: the technical details about each hardware component

• Eg: a computer system might be configured to include a printer; the specification of the printer might be a print speed (8pages/1min), or the capacity to print in color

Data and Processing

The hardware and software of a computer system work together to process data

• Data: the words, numbers, figures, sounds, graphics that describe people, events, things, and ideas

• Processing: modifying the data• Processing tasks occur on the motherboard

which is located inside the computer and is the main electronic component of the computer

Motherboard

• Motherboard: a circuit board which is a rigid piece of insulating material with circuits, electrical paths, on it that control specific functions

Motherboard Processing Hardware

• Microprocessor or the Central Processing Unit (CPU):

• Consists of transistors and electronic

circuits on a silicon chip (an integrated

circuit embedded in semiconductor

material)• Mounted on the motherboard and is

responsible for executing instructions

to process information

Motherboard Processing Hardware

• Cards: are removable circuit boards that are inserted into slots in the motherboard to expand the capabilities of the motherboard

• Eg: Sound card translates the

digital audio information from the

computer into analog sounds

that the human ear can hear

Input and Output

• Input: data or instructions you type into the computer

• Output: the result of the computer processing input

• Peripheral Devices: components are needed to accomplish input, output, and storage functions

Input Devices

• Keyboard and mouse are input devices that are used to enter data and issue commands

• Commands: are input instructions that tell the computer how to process data (e.g. ms words commands)

Output Devices

• Output can be in many different forms:– Reports– Documents– Graphs– Sounds– Pictures

• The output forms are produced by output device e.g. monitor and printer

• The output created can be stored either inside the computer or in external storage device (e.g DVD)

Comparing CPU Speeds

• How fast a computer can process instructions depends partially on the speed of the microprocessor, which is determined by its:

– Clock Speed

– Word Size

– Cache Size– Whether it is single or dual core

Comparing CPU Speeds

• Clock Speed: is measured in megahertz (MHz), millions of cycles per second, or in gigahertz (GHz), billions of cycles per second

• Word Size: the amount of data the is processed at one time

• Dual-Core processor: has two processors on a single chip, can process information up to twice as fast as single-core processor (one with one processor on the chip)

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