macquarie fields college of tafe version 2 – 13 march 2000 4 - hardware 4

Macquarie Fields College of TAFE

Version 2 – 13 March 20004 - HARDWARE

4

Computer Systems

• Two Basic Areas:

• Hardware Hardware (already covered)

• SoftwareSoftware

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Controls the processing and movement ofdata within the computer system

Software

• Systems software

– Controls entire computer system

– Provides link between hardware and applications

– Stored in part or full in ROM

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Software

• Operating Systems

– Performs many tasks

– Instructs the CPU on how to start and instructions are stored in ROM

– Configures Hardware

– Management Tools

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Software

• Application Software

• Program/Set of Programs (suite)

– Allows user to perform a wide variety of tasks

– Word Processing

– Spreadsheets

– Database

– Desktop Publishing

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Software

• Utility

• Manages the Resources of the computer

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Two or more computers linked together

Network

• LANLocal Area Network

• WANWide Area Network

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Network Topology (Architecture)

• Bus

• Ring (token)

• Star

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Operating Systems

• DOS – Disk Operating System

• UNIX

• OS/2

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Local Area Networks (LAN)

A local area network is a group of computers that are connected so

that they can exchange messages and files and

share resources like printers.

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Local Area Networks (LAN)

• Number of computers linked together

• Small geographical area

• Privately owned

• Fast transmission speed

• Relatively low cost

• 2-100 Mbps

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Wide Area Networks (WAN)

• Large Geographical Area

• Privately or Public owned

• Many Devices

• Mainframes

• File Servers

• Uses Public Lines

• High Cost

• Slower – 9600-33600 Mbps

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Bus Architecture

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Bus Architecture

• Connects all nodes to a single bus

• A signal addressed to another node is sent from a microcomputer to the bus

• The other node recognises the addressed signal and accepts it

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Advantages and DisadvantagesBus Architecture

• Advantages• Since each node is separately

connected to the network, any node can break down without affecting other nodes

• Bus networks are relatively inexpensive and easy to install for small networks.

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Ring Architecture

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Ring Architecture

• Arranges the nodes on a network in a circle

• When one of the microcomputers on the network sends a signal, it passes it to the next node on the network

• If it is not addressed to that node, it is transmitted to the next node

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Advantages and DisadvantagesRing Architecture

• Advantages• Offer high bandwidth and can span large

distances. • Disadvantages• If one node breaks down, the entire

network breaks down• Expensive and difficult to install• A ring network requires rewiring when

new equipment is added

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Star Architecture

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Star Architecture

• Nodes are connected to a central, or host, computer

• Signals are transmitted via the host

• There are no direct connections between the nodes on the network except through the host computer

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Advantages and DisadvantagesStar Architecture

• Advantages• Star networks are relatively easy to install

and manage • If a node breaks down, no harm is done.

The others continue to function• Disadvantages• If the host breaks down, so does the

network• Bottlenecks can occur because all data

must pass through the hub.

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Mixed Topologies

These topologies can also be mixed. For example, a bus-star network consists of a high-bandwidth bus, called the backbone,

which connects a collections of slower-bandwidth star segments.

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