Macquarie Fields College of TAFE
4
Version 2 – 13 March 2000
4 - HARDWARE
Macquarie Fields College of TAFE
Computer Systems
• Two Basic Areas:
• Hardware (already covered)
• Software
Controls the processing and movement of
data within the computer system
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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
Two or more computers linked together
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Network
• LAN
Local Area Network
• WAN
Wide 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.
Macquarie Fields College of TAFE
Local Area Networks (LAN)
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Number of computers linked together
Small geographical area
Privately owned
Fast transmission speed
Relatively low cost
2-100 Mbps
Macquarie Fields College of TAFE
Wide Area Networks (WAN)
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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 Disadvantages
Bus 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
Macquarie Fields College of TAFE
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
Macquarie Fields College of TAFE
Advantages and Disadvantages
Ring 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
Macquarie Fields College of TAFE
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
Macquarie Fields College of TAFE
Advantages and Disadvantages
Star 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 slowerbandwidth star segments.