The basic components of a single CD-Rom workstation are a microcomputer and a CD-ROM drive. A printer will be necessary if you want to obtain a paper copy of searches and if you wish to do an online search to update CD-ROM search a modem and a telephone line will also be needed. If more than one person needs to use the system at a time, networking has to be taken, recourse to. The ideal CD-ROM configuration offers multi-user access to many databases.
The advantages of putting CD-ROMs on a network are providing multiple concurrent access to information and help in streamlining of the disks themselves which otherwise would be distributed and loaded manually.
CD-ROM networks are normally mounted on PC-based local area networks. Standard available LANs do not properly support the use of CD-ROM, and require additional software add-ons to manage the optical drives. These are generally controlled by a separate optical file server (i.e., a computer adapted with CD controller cards to which drives are attached).
There are three alternative architectures for implementing CD-ROMs on a network. These are:
i) a file server arrangement with the data files located on the file server itself, and the user interface and the search engine residing on the client workstation;
ii) a centralised approach, where both data and search engine and interface reside on a multi-user machine, with the workstation acting as a terminal;
iii) a client-server approach, where the data files and the search engine reside on the server machine, and the, user interface with the client workstation. This arrangement reduces the communications load by keeping the processing close to the data storage, and enables the full power of the workstation to be available to the client.
At present, CD-ROMs running on local area networks have to compromise with all these basic aspects.