Computer Hardware and Software
Jack G. ZhengJune 15th 2005
MIS XLM.A
Overview
• Computer Categories by Size
• Two major categories of information technology– Software– Hardware
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
Software
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– …
Application Software (2)
• Organizational level software/system: software used for businesses at the organizational level– Vertical market software
• Unique to a particular industry or organization• Examples: MARTA scheduling software; student
management software; pilot training software
– Horizontal market software• General to several or all industries• Examples: accounting, payroll, billing, human resources• This type of software is very likely to be purchased off-
the-shelf
System Software
• Operating systems software (OS)
• Utility software
• [Other categories]– System/server management– Development software
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
• Multitasking and [multiprocessing]
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, …
Exercise
• Are the following products software? What types are they?– Adobe Acrobat Reader– WinZIP– “SimCity 2000”– Redhat– Sassar– WebCT– Digital photos, MP3 songs
Hardware
Hardware Categories
• Input
• Output
• Processing
• Storage
• Connecting and interface
• Networking and 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, cameral, 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: Anthlon
• 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.14 on page 56)– 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.21 on page 63):– 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]
• Hot swap and PnP (Plug and Play)
Networking and Telecommunication
• Router
• Modem– Mo-dulation: digital to analog– Dem-odulation: 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
Summary
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/