Computer Hardware and Software

Jack G. ZhengMay 13th 2008

MIS XLM.A

Overview

• Two major categories of information technology– Software– Hardware

Software

• What is software?– Computer instructions– No physical existence

Hardware

System Software

Application Software

Data

Operating System (OS)

Software Types

• Application software– Performs specific information processing

tasks

• System software– Manages and supports operations of

computer systems and networks (including hardware and application software)

Application Software (1)

• Personal (productivity) software– Office suites

• Word processor, spreadsheet, presentation, desktop publishing, web authoring

– Communications• Messenger, email

– Graphic and media processing– Education software– Entertainment software– …

• Organizational level software/system: software used for businesses at the organizational level

System Software

• Operating systems software (OS)

• Utility software

• [Other categories]– System/server management– Development software– etc.

Operating System Software

• Operating systems (OS)– A basic platform to control computer– Work with hardware, especially processors– Support application software

• Examples– Windows 95, NT, 98, Me, 2000, XP, 2003, CE– Mac OS– Unix, Solaris, Linux– NOS (network operating system): Novell

Utility Software

• Utility software– Adds additional functionality to the OS– More and more of them are becoming part of OS

now

• Some types– Anti-virus: Norton, McAfee– Uninstaller– Disk optimization software– Crash-proof software– System monitoring, CD/DVD Writing, disk

simulation, …

Question

• Are the following products software? What types are they?– Open office– Skype– Sims– PartitionMagic– VMware

Hardware

Hardware

• Physical computing devices

Output

Storage

Input Processing

Connection Device and Interface Communication

Common Input Devices

• Keyboard• Point devices

– mouse, trackball, pointing stick, touchpad, optical pen

• Touch screen• Game controller• Scanner

– image scanner, bar code reader, optical mark recognition (OMR)

• Multimedia– microphone, camcorder, camera, webcam

Common Output Devices

• Monitor– CRT (cathode ray tube), LCD (liquid crystal

display), Plasma– Some important specifications

• Viewable image (screen) size• Resolution• Dot pitch

• Printer– Inkjet, Laser, [Dot matrix], multi-functional– DPI (Dot Per Inch)

Processing

• CPU (central processing unit)– Central command processing device

• Major manufacturers (for PC)– Intel: Pentium 2, 3, 4, Celeron– AMD: Athlon

• Speed: number of cycles per second– Megahertz (Pentium 3), Gigahertz (Pentium 4)– Moore’s law

• How it works (figure A.19 on page 60)– You can visit Intel museum (in Santa Clara or online)

Data/Storage Units

• Data units by size– Bit (0 or 1)– Byte (character): 8 bits– Kilobyte (KB): 1024 bytes– Megabyte (MB): 1024 KB– Gigabyte (GB): 1024 MB– Terabyte (TB): 1024 GB

• ASCII (American Standard Code for Information Interchange)– 27(128) characters

• [UNICODE]– New standard for character representation with 231

possibilities

Primary Storage (Memory)

• Memory– Made of silicon– Electronically stores data– Very fast, relatively expensive and smaller

storage size

• Type– RAM: random access memory

• Temporary storage• “640k should be enough for anybody” – Bill Gates, 1981• Today: 512MB recommended

– [ROM]: read only memory• Flash ROM

Secondary Storage Devices

• Secondary storage– Slower, less expensive, permanent storage,

bigger storage size

• Common devices (see figure A.12 on page 53)– Magnetic: hard drive/disk, floppy, ZIP– Optical: CD/DVD serials– Flash memory:

• Flash memory (jump drive)• Cards: CompactFlash, SmartMedia, xd-Picture Card …

Connection Devices

• Common interfaces/ports (see figure A.17 on page 58):– Traditional

• Serial port• Parallel port: for printer• PS/2: keyboard and mouse

– Fast connection• USB (universal serial bus)• USB 2.0 (480Mbps)• IEEE 1394 (firewire): 400Mbps

– Wireless• Infrared• Bluetooth (30 feet) • WiFi for wireless computer network (300 feet)

• [Motherboard/mainboard]

Networking and Telecommunication

• Router

• Modem– Modulation: digital to analog– De-modulation: analog to digital– Types

• Phone modem: up to 56Kbps• DSL modem: 128K to 8M• Cable modem: 512K to 20M• Satellite modem: 6M up

• Other networking devices– See more in XLM.E

Computer Categories by Size (1)

• PDA (Personal Digital Assistant)

• Microcomputer (personal computer)– Notebook/laptop/tablet– Desktop/workstation

• Minicomputer– Mid-ranged computer that can

support departmental use

Computer Categories by Size (2)

• Mainframe– Large scale computer for organizational

use– Historically used in centralized

computing

• Supercomputer– The fastest, most powerful computer,

usually used for scientific research– Earth Simulator 1

• Used for climate simulation• 5120 processors and 2GB RAM per

processor

1 Source: http://www.top500.org

Good Resources

• How computer works– http://computer.howstuffworks.com

• Intel museum– http://www.intel.com/intel/intelis/museum/

• Computer DIY– http://compreviews.about.com/od/tutorials/

• IEEE history of computing– http://www.computer.org/history/