Networking personal computers - Wiley Online Library

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combines the advantages of both independent PC oper- ation and ... Some disadvantages include: -- no industry standard (however progress is occurring) lack of networking applications software (a situation that is rapidly ... The network leaves the built-in computer RS- ..... The system can easily be tailored for individual.
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Networking Personal Computers ROBERT P LEARMONTH

The Russell Grimwade School of Biochemistry University of Melbourne Parkville, 3052, Australia Introduction This paper is intended to help and encourage others who are contemplating setting up a network of personal computers (PCs), by providing a brief overview of networking concepts and terminology, and describing the features of an installed system. The Department of Biochemistry has used computers for teaching applications over two decades and is now well served by a local area network of IBM personal computers. The advantage of reduced time spent on computer management chores has justified our efforts to establish a network. Why Network? The main reason for the establishment of the network described in this paper was the logistic problem of maintenance, validation and updating of floppy discs for student use. The use of a microcomputer network combines the advantages of both independent PC operation and centralised computing. Some advantages include: --- simplification of the user interface sharing of software sharing of peripheral equipment (eg one printer services requirements of all workstations) interpersonal communication (electronic mail) security of software --better price/performance ratio than centralised computing - - l o w e r 'up front' costs than a minicomputer and terminals incremental growth path (can add more microcomputers to an existing network) - - i t is not necessary to provide disc drives on computers used as workstations, potentially reducing costs and increasing security. Some disadvantages include: - - no industry standard (however progress is occurring) lack of networking applications software (a situation that is rapidly improving) - - s o f t w a r e support (to rectify a problem a user may have to contact up to three sources, network hardware vendor, network software vendor and applications software vendor) cost of provision and installation of cabling, network interfaces and networking software (compared to stand-alone microcomputers) staff time for network support and maintenance (once installed, maintenance time should be low however, a technically competent person must be on hand). In an environment where greater restraint is being BIOCHEMICAL EDUCATION 17(2) 1989

placed on teaching resources, the advantages and improvements in efficiency offered by connecting standalone computers, combined with decreasing hardware costs, make networking an attractive proposition.

What is a Computer Network? A computer network is an interconnected collection of autonomous computers able to share programs and data. This is in contrast to the master/slave relationship between a host (mainframe) computer and a dumb terminal. In a network the connected computers act as 'intelligent' terminals with their own file storage facilities, each capable of independent operation. The network connections may be via wire cables, fiber-optics, or even radio waves and satellites. The majority of small networks use twisted pair wires (as in telephone lines) or coaxial cables. The term Local Area Network (LAN) refers to a small network encompassing a building or campus, covering distances of up to 5 km. In addition to microcomputer workstations, numerous other types of device may be connected to the network, such as file servers, print servers and communications servers which coordinate and queue multiple requests for access to peripheral file stores, printers and communication with outside systems. A Local Area Network of IBM Microcomputers The network in the Department of Biochemistry, University of Melbourne currently comprises eight IBM JX microcomputers and an IBM AT clone which acts as a dedicated file- and print-server. The user nodes are located in carrels adjacent to the teaching laboratories (Fig 1). The computers are connected in a bus topology, t

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81 using IBM PC Cluster hardware interfaces and Novelle networking software (Advanced Netware 86 v2.0a). The IBM JX is essentially a compact, cheaper version of the IBM PC. Although this machine is more limited in terms of availability of expansion modules, for most applications it operates in the same manner as the standard IBM PC. The network bus consists of RG59/U 751) coaxial cable with standard BNC connecting hardware (Fig 2). The bus may be up to 1000 m in length, with BNC terminating plugs at each end to prevent standing wave interference. Nodes may be connected by breaking the cable and inserting BNC T-pieces. A computer may thus be connected directly to the backbone cable, or via a 'drop cable' which must be 1-5 m in length. Block Copper braid plastic

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The IBM JX workstations are capable of independent operation with the option of connecting to the network. This involves running a program to establish a logical connection and then logging in to the network. Staff generally use this mode of operation to utilise network functions and printing facilities, while storing their own programs and data on floppy discs. For use by students, workstations are configured to start up automatically through the network file server, obtaining all programs and data from the central hard disc. This simplifies the user interface to the extent that students need only turn a computer on. A menu of options is loaded automatically and students are presented with their own operating environment, so they need never be exposed to the computer operating system.

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