The service is available in more than thirty facilities distributed throughout College. It is based on the following components:
This ROM program first places an IPX-based query over the network to a local NetWare server to determine which initialisation program (boot image) is appropriate for the particular workstation. A database which matches each workstation's Ethernet MAC address to a particular boot-image file is maintained on the server, and a server process is kept running for the purpose of responding to such queries. The response given to the workstation identifies the appropriate boot image and the server where it is located.
Having identified the appropriate boot-image file, the ROM program makes a connection -- again using IPX -- to the server where the file is located, and loads the boot-image into memory on the workstation. Under control of the boot-ROM program, this memory now appears as a virtual A-drive system diskette containing appropriate system initialisation files. These files are used to start the system up, just as might be done from a real diskette or hard drive.
When a workstation has been initialised, all the necessary programs have been loaded to provide memory management and IPX network access, a connection has been made to one of the preferred initial NetWare server, the hard disk has been cleaned of files left over from any previous use, and the login prompt is displayed.
At this stage, the user must log in to one of the NetWare servers on the College network in order to use the service. Server- and user-specific login scripts are used to complete initialisation of the user's work session.
Standard procedures allow tailoring of boot images to accomodate the different workstation hardware configurations (special screens, particular Ethernet adapters, availability or not of hard disk, etc) and different location-specific preferences (initial NetWare server, default printer, automatic forced login, etc) while maintaining a consistent presentation to the user.
Certain applications are not widely in demand, but are of key importance in particular disciplines. These specialist applications are provided to the particular community of interest by making them available on the relevant server or servers.
Today, most supported PC applications are based on Microsoft Windows. A diminishing proportion of DOS applications continues to be supported.
Each supported application belongs in a well-defined set of directories on a publicly-readable file volume on the NetWare file server(s) on which it is made available. As a matter of course, the same location is used consistently from one server to another. This not only simplifies user access to the application, but also allows the use of standard procedures to ensure that each application is configured uniformly across all servers, thus facilitating user support.
Microsoft Windows itself is an application which provides the context for delivery of all Windows-based applications. The same approach to common directory naming and to uniformity of configuration is used in maintaining this key application.
In addition, a hierarchical icon-based menu application is used to guide the user in selecting the desired application.
Its successful operation depends on standard network administration procedures which ensure appropriate correspondence between the network addresses used for IPX and for IP in each part of the College network. This correspondence allows the IPX network number (available to the workstation during login) to be saved in the DOS environment and used to identify the appropriate configuration file for initialisation of Winsock.
Each such configuration file specifies the appropriate network mask, gateway address and resolver host addresses for the corresponding part of the network. The workstation's IP address is determined using a RARP query sent to a server process running on a convenient local NetWare or Unix server.
The key Internet application is the World Wide Web. In order to reduce delay in accessing remote Web pages and at the same time to conserve external bandwidth, UCD Computing Services operates a caching Web server which mediates external Web access from workstations in College, including those belonging to the Student PC Service. The standard Web browser configuration takes advantage of this facility.
Draft printing is provided via print queues on the NetWare file-and-print servers which are services by printers connected to the College network. Utilities are provided for both DOS and Windows which allow any available print queue to appear to the workstation application as a locally attached printer.
Student laser printing is a chargeable service provided at particular workstations using a directly-attached printer fitted with a charge-card device. The common Windows configuration allows a workstation user (and this is quite usual) to select a laser printer as the default printer even when one is not directly attached so that the document preview of any Windows application can work realistically.