Computer Hardware

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Computer Hardware
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Outline of Lecture

• Classification of computers
• Classification of applications
• Time-shared vs. single-user computing
• Networked computing
• PCs vs. workstations
• NetPCs, Network Computers
• Downsizing

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Classification of Computer Systems

• Microcontrollers
• Microcomputers
• IBM compatible Personal Computers
• Apple Macintosh
• Engineering Workstations
• Minicomputers
• Mainframes
• Supercomputers
• Networks

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Microcontrollers

• Microcontrollers contain all of the essential
  functions of a computer on a single chip!
• Processing
• memory
• input/output
• Sometimes combined with several other chips on a
  single board
• Ideal for low-cost, dedicated applications
• Cost 1 - 1000

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Microcontroller Links

• Motorola Microcontroller Site
• Motorola MC68HC11 Microcontroller
• Microcontroller FAQ/primer

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Microcontrollers

• There is more computer power under the hood of a
  new car than Neil Armstrong had in his lunar
  lander!

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Microcomputers

• Typically single user desktop computers
• Highly interactive
• Most popular for home and business applications
• There are two major standards
• IBM compatible PCs (Wintel)
• Apple Macintosh
• Cost 1000 - 5000

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Engineering Workstations

• More powerful than PCs
• Generally non-Intel, RISC CPU, and UNIX operating
  system
• Main players are Sun Microsystems,
  Hewlett-Packard, IBM, Digital and Silicon
  Graphics
• Best for demanding engineering applications like
  CAD
• Cost 5000 - 50,000

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Minicomputers

• Generally multi-user, time shared
• Emphasis on processing, not interaction
• Usually proprietary CPU, operating system
• Examples are IBM AS/400, Digital VAX
• Used for departmental data processing
• Cost 20,000 - 100,000

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Mainframes

• At one time, these were the only kind of
  computers
• Mainframes can support hundreds of simultaneous
  users
• They provide little graphical interaction
• Similar to minicomputers, but larger and more
  expensive
• Used for divisional or corporate data processing
• Cost 100,000 - 1 Million

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Supercomputers

• These are the most powerful computers available
• Their main application is in scientific research
• Usually use many CPUs processing in parallel
• Cost 1 million - 30 million

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Types of Application

• Interactive-class
• Real-time user interaction
• Capacity-class
• These are moderately large number crunching
  applications (e.g. finite element analysis)
• Capability-class
• The problems are very large, and solutions are
  time critical

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Types of Application

• Input/output-bound operation
• limited by I/O speeds
• primarily administrative jobs
• Processor-bound operation
• limited by processor speed
• primarily scientific jobs

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Relative Speed of Computers
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Time-shared, Multi-user Computing

• All processing is done on a single, large
  computer
• Many users are connected through terminals
• Controlled by the computer priesthood
• Most corporate systems (banks, etc.) are in this
  class
• Telnet is a popular protocol for connecting to
  time-shared systems - here are a couple of
  examples
• UWO Panther login
• UWO Libnet library computer

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Time-shared, Multi-user Computing

• Advantages
• terminals are cheap
• control and administration is centralized
• resources are shared

• Disadvantages
• mainframes are expensive
• response is very slow
• usually no graphics

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Single-user, Stand-alone Computers

• These are personal computers
• Controlled by the user
• Many home computers are in this class

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Single-user, Stand-alone Computers

• Advantages
• PCs are cheap
• fast response
• interactive graphics
• no technical support staff required

• Disadvantages
• sharing of software, resources is difficult
• users must be knowledgeable
• no technical support staff available

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Workstation Clusters or LANs
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Workstation Clusters or LANs

• Advantages
• shared resources such as printers, disks,
  software
• transparent communication
• much greater capability than independent
  workstations
• control and administration are centralized

• Disadvantages
• more complex and expensive than stand-alone PCs
• technical support staff required

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Network Computers

• Low cost computers connected to network
• No local disk - all software downloaded from
  server
• Run Java programs
• Champions include Sun Microsystems and Oracle
  Corp.

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Network Computer Links

• Oracles NC site
• Suns JavaStation

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Network Computers

• Advantages
• low cost
• easy administration
• easy to use

• Disadvantages
• limited power
• requires network
• no software

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NetPCs

• Microsoft and Intels answer to the network
  computer
• Combines the best features of the NC without
  sacrificing the benefits of the PC

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NetPC Links

• Microsoft
• Intel

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NCs versus NetPCs links

• Microsofts argument
• Byte comparison
• part 1
• part 2

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Comparison of PCs and Workstations

• simple
• easy to use
• limited
• inexpensive
• popular

• complex
• hard to use
• powerful
• expensive
• elite

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Comparison of PCs and Workstations
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Comparison of PCs and Workstations
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The Windows NT Workstation

• PCs are becoming more powerful
• new operating systems like Windows NT
• powerful chips like the Pentium, Pentium II
• large disks, memory
• powerful 3D graphics
• High-end PCs are now comparable to mid-range Unix
  workstations in terms of performance, at much
  lower cost.
• NT workstations are gaining rapid market share

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NT vs. Unix Links

• Unix vs. NT story in Byte
• Unix vs. NT evaluation from CMP Media

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Price/performance Comparison
Source Paradigm Shift, Tapscott and Caston, 1993
MIPS millions of instructions per second
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Downsizing

• Many companies are replacing mainframes and
  minicomputers with networked PCs Unix or NT
  servers

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Summary

• Classification of computers
• Classification of applications
• Time-shared vs. single-user computing
• Networked computing
• NetPCs, Network Computers
• PCs vs. workstations
• Downsizing