4 Macquarie Fields College of TAFE Version 2 – 13 March 2000 4 - HARDWARE

Computer Systems Two Basic Areas: Hardware (already covered) Software 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

Software Systems software Controls entire computer system Macquarie Fields College of TAFE Software Systems software Controls entire computer system Provides link between hardware and applications Stored in part or full in ROM

Software Operating Systems Performs many tasks Macquarie Fields College of TAFE Software Operating Systems Performs many tasks Instructs the CPU on how to start and instructions are stored in ROM Configures Hardware Management Tools [Hyperlink will take you to Operating Systems]

Software Application Software Program/Set of Programs (suite) Macquarie Fields College of TAFE Software Application Software Program/Set of Programs (suite) Allows user to perform a wide variety of tasks Word Processing Spreadsheets Database Desktop Publishing

Software Utility Manages the Resources of the computer Macquarie Fields College of TAFE Software Utility Manages the Resources of the computer

Two or more computers linked together

Network LAN Local Area Network WAN Wide Area Network Macquarie Fields College of TAFE Network LAN Local Area Network WAN Wide Area Network [Hyperlink will take you to Local Area Networks – LAN] [Hyperlink will take you to Wide Area Networks – WAN]

Network Topology (Architecture) Macquarie Fields College of TAFE Network Topology (Architecture) Bus Ring (token) Star [Hyperlink will take you to Bus Architecture] [Hyperlink will take you to Ring Architecture] [Hyperlink will take you to Star Architecture]

Operating Systems DOS – Disk Operating System UNIX OS/2 Macquarie Fields College of TAFE Operating Systems DOS – Disk Operating System UNIX OS/2 [Hyperlink will return you to Software]

Local Area Networks (LAN) Macquarie Fields College of TAFE 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.

Local Area Networks (LAN) Macquarie Fields College of TAFE Local Area Networks (LAN) Number of computers linked together Small geographical area Privately owned Fast transmission speed Relatively low cost 2-100 Mbps [Hyperlink will return you to Network]

Wide Area Networks (WAN) Macquarie Fields College of TAFE 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 [Hyperlink will return you to Network] Mbps – Million Bits per second

Macquarie Fields College of TAFE Bus Architecture

Bus Architecture Connects all nodes to a single bus Macquarie Fields College of TAFE 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 Connects all nodes to a single bus much as the components are organised within a computer. A signal addressed to another node is sent from a microcomputer to the bus. All other nodes on the network, which are also connected to the same bus, examine the signal. The other node recognises the addressed signal and accepts it. If the signal is not for that node it ignores it.

Advantages and Disadvantages Bus Architecture Macquarie Fields College of TAFE 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. [Hyperlink will return you to Network Topology (Architecture)] Since each node is separately connected to the network, any node can break down without affecting other nodes This feature makes bus architecture one of the most popular arrangements for networks

Macquarie Fields College of TAFE Ring Architecture

Ring Architecture Arranges the nodes on a network in a circle 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 If it is not addressed to that node, it is transmitted to the next node and so on around the circle until it reaches the node it is addressed to.

Advantages and Disadvantages Ring Architecture 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 [Hyperlink will return you to Network Topology (Architecture)] Because each node on the network transmits any signal that is not addressed to it, if one node breaks down, the entire network breaks down Unlike the other two systems, where new equipment can be plugged into the bus or host computer, A ring network requires rewiring when new equipment is added. To insert a new node, the connection between two existing nodes must be broken. The new node is then installed and wired to the two adjacent nodes.

Macquarie Fields College of TAFE Star Architecture

Star Architecture Nodes are connected to a central, or host, computer Macquarie Fields College of TAFE 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 Signals are transmitted via the host, that is, when one of the microcomputers on the network sends a signal, it is sent to the host, which routes it to the node it’s addressed to.

Advantages and Disadvantages Star Architecture 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. If the host breaks down, so does the network as programs are running off the file server.

Macquarie Fields College of TAFE 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. [Hyperlink will return you to Network Topology (Architecture)]