Transcript Computer Hardware

Chapter
3
Computer Hardware
McGraw-Hill/Irwin
Copyright © 2011 by The McGraw-Hill Companies, Inc. All rights reserved.
Learning Objectives
• Understand the history and evolution of
computer hardware.
• Identify the major types and uses of
microcomputer, midrange, and
mainframe computer systems.
• Outline the major technologies and uses
of computer peripherals for input, output,
and storage.
3-2
Learning Objectives
• Identify and give examples of the
components and functions of a computer
system.
• Identify the computer systems and
peripherals you would acquire or
recommend for a business of your choice,
and explain the reasons for your selection.
3-3
Early Computing
• 1880s
– Punched cards turned sensors On or Off
• 1946
–
–
–
–
ENIAC
First Digital computer - programmable
Used vacuum tubes
Would fill room 39 ft by 39 ft
• Late 1950s
– Transistors replaced vacuum tubes
– Smaller, faster, cooler
3-4
Waves of Computing
• First Generation - Prior to 1950
– Vacuum tubes
• Second Generation - Late 1950s
– Transistors & integrated circuits – Jack Kilby
– 200,000 to 250,000 calculations per second
• Third Generation - Mid-1960s
– Integrated circuitry and miniaturization
• Fourth Generation - 1971
– Further miniaturization
– Multiprogramming and virtual storage
• Fifth Generation - 1980s
– Millions of calculations per second
3-5
Age of Microcomputers
• 1975
– MITS introduced ALTAIR 8800.
• 1977
– Commodore and Radio Shack
• 1979
– Apple computer, fastest selling
– Steve Jobs & Steve Wozniak
• 1982
– IBM introduced the PC
– Changed the market
3-6
Information Appliances
• Hand-held microcomputer devices
• Known as personal digital assistants (PDAs)
–
–
–
–
–
Web-enabled
Touch screens, handwriting recognition, keypads
Access email or the Web
Exchange data with desktop PCs or servers
Latest entrant is the BlackBerry
• PDAs include
– Video-game consoles
– Cellular and PCS phones
– Telephone-based home email appliances
• iPhone 4
3-7
Midrange Systems
• High-end network servers
– Large-scale processing of business applications
• Not as powerful as mainframes
– Less expensive to buy, operate, and maintain
• Often used to manage
– Large Internet websites
– Corporate intranets and extranets
– Integrated, enterprise-wide applications
• Used as front-end servers
– Assist mainframes with telecommunications and
networks
3-8
Mainframe Computer Systems
• Large, fast, powerful computer systems
– Large primary storage capacity
– High transaction processing
– Handles complex computations
• Widely used as superservers for…
– Large client/server networks
– High-volume Internet websites
• Becoming popular computing platform for…
– Electronic commerce applications
– Data mining and warehousing
3-9
Supercomputer Systems
• Extremely powerful systems
– Scientific, engineering, and business applications
– Massive numeric computations
• Markets include…
– Government research agencies
– Large universities
– Major corporations
• Uses parallel processing
– Billions to trillions of operations per second
• (gigaflops and teraflops)
– Costs $5 to $50 million
3-10
Storage Capacity Measurement
•
•
•
•
•
Kilobyte (KB): one thousand bytes
Megabyte (MB): one million bytes
Gigabyte (GB): one billion bytes
Terabyte (TB): one trillion bytes
Petabyte (PB): one quadrillion bytes
3-11
Types of Semiconductor Memory
• Random Access Memory (RAM)
– Most widely used primary storage medium
– Volatile memory
– Read/write memory
• Read-Only Memory (ROM)
– Permanent storage
– Can be read, but not overwritten
– Frequently used programs burnt into chips
during manufacturing process
– Called firmware
• Flash Drive
3-12
RAID Storage
• Redundant Arrays of Independent Disks
– Arrays of hard disk drives
– Virtually unlimited online storage
– 6 to more than 100 small hard disk drives in a
single unit
– Data are accessed in parallel over multiple
paths from many disks
– Redundant storage of data on several disks
provides fault-tolerant capacity
– Storage area networks can interconnect many
RAID units
3-13
Radio Frequency Identification (RFID)
• One of the newest and fastest growing
storage technologies
– System for tagging and identifying moving objects
• Merchandise, postal packages, casino chips, pets
– Tag 1 inch square
– Chips half the size of a grain of sand
• Passive chips derive power from reader signal
• Active chips are self-powered
• Privacy Issues
3-14
Predictions for the Future
•
•
•
•
•
Biological memories
Health remedies
Longer life spans
Virtual activities
Memory recall
3-15