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

Computer Systems Two Basic Areas: HardwareHardware (already covered) SoftwareSoftware Macquarie Fields College of TAFE

Controls the processing and movement of data within the computer system

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

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

Two or more computers linked together

Network LAN Local Area Network WAN Wide Area Network Macquarie Fields College of TAFE

Network Topology (Architecture) Bus Ring (token) Star Macquarie Fields College of TAFE

Operating Systems DOS – Disk Operating System UNIX OS/2 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. 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 Mbps 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 – Mbps Macquarie Fields College of TAFE

Bus Architecture 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 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. Macquarie Fields College of TAFE

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 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 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. 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. Macquarie Fields College of TAFE