IS Fall 2009 Chapter 2: Hardware 1/14/2010

Objectives What exactly is a computer, and what are its four main functions? What is the difference between data and information? 1/19/2010IS 2101/07---Spring 20102

Objectives What are bits and bytes, and how are they measured? What devices do you use to get data into the computer? 1/19/2010IS 2101/07---Spring 20103

Objectives What devices do you use to get information out of the computer? What’s on the front of your system unit? 1/19/2010IS 2101/07---Spring 20104

Objectives What’s on the back of your system unit? What’s inside your system unit? 1/19/2010IS 2101/07---Spring 20105

Objectives How do you set up your computer to avoid strain and injury? 1/19/2010IS 2101/07---Spring 20106

Data Processing Input Process Output Store 1/19/2010IS 2101/07---Spring 20107

Information vs. Data Information is organized – Phone book Information is more valuable than data 1/19/2010IS 2101/07---Spring 20108

Bits and Bytes Representing information – Electrical flow: on or off – A bit has two possible values – Put bits together to represent more complex information (alphabet of two letters) Measuring information 1/19/2010IS 2101/07---Spring 20109

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Input Hardware Text input: keyboard Pointer input: mouse and stylus Sound: microphones Light: cameras Measurements: thermometer 1/19/2010IS 2101/07---Spring

Connecting Wire connections Wireless – Infrared (line of sight) – Radio (subject to interference) 1/19/2010IS 2101/07---Spring

Keyboards Variety of arrangements – Major: QWERTY vs. Dvorak – Minor: specialized keys and function keys – Numeric pads – Special functions Special characters: beyond English 1/19/2010IS 2101/07---Spring

Pointers Detecting motion – Mechanical – Optical (not good on clear glass) Buttons Scroll wheel Joysticks Trackballs Touchpads 1/19/2010IS 2101/07---Spring

Everything’s Customizable What each button on a keyboard or mouse does can be customized You probably wouldn’t want to change most of them Utilities are provided to map various extra buttons to different functions 1/19/2010IS 2101/07---Spring

Output Devices Video: Monitor, projector Printer Speakers Motors 1/19/2010IS 2101/07---Spring

Monitors Pixels – Resolution – Color depth RGB Aspect ratio 1/19/2010IS 2101/07---Spring

Printers Technology – Impact – Inkjet – Laser Quality Cost Speed 1/19/2010IS 2101/07---Spring

System Unit Power Processor Memory Storage Peripheral connectors 1/19/2010IS 2101/07---Spring

Processor Central Processing Unit Directs the operations of the computer and carries out computations Computers generally have several special purpose processors as well, such as for graphics – These may be more powerful than the CPU 1/19/2010IS 2101/07---Spring

Processor Design Different processors operate differently Programs for computers usually have to be designed for a particular process – And for other characteristics we’ll talk about later 1/19/2010IS 2101/07---Spring

Processor Characteristics Number of cores Clock speed Data width and bus width 1/19/2010IS 2101/07---Spring

Heat Computers use a great deal of energy when running Almost the only output for that energy is heat – Very few moving parts Computers can overheat and damage themselves without adequate cooling The CPU is particularly vulnerable 1/19/2010IS 2101/07---Spring

Memory Used by the computer to store data and programs in active use Fast, relatively expensive, volatile Usually called RAM (Random Access Memory) 1/19/2010IS 2101/07---Spring

Price changes My first computer: 16 K memory was $300 Today: 2 G memory is $100 In price per Meg: – Old: $19,200 – New: $0.10 1/19/2010IS 2101/07---Spring

System Unit Main board Extension cards plug in to main board Memory plugs into main board 1/19/2010IS 2101/07---Spring

Storage Relatively cheap Slower Large volume Not volatile Read-only vs. Read-write 1/19/2010IS 2101/07---Spring

Storage Technology Generally, data stored on disks in concentric circles Terminology – Platters, tracks, cylinders Read/Write heads Speed – Rotation speed – Seek speed – Data transfer speed 1/19/2010IS 2101/07---Spring

Connectors 1/19/2010IS 2101/07---Spring

Connectors Video Mouse and Keyboard USB Parallel Serial Firewire Ethernet 1/19/2010IS 2101/07---Spring

Ergonomics Chair height Monitor height Wrist support Repetitive stress Hearing damage 1/19/2010IS 2101/07---Spring