Terminal Emulator Task Force Report

Horizontal Rule [MAR 95]

Manfred Chan,Gary Fung, Angela Tang

[working]The existing terminal emulators used at City University, PCTERM and PC240, were developed by the Computer Centre in 1987. The emulators are DOS-based and contain many excellent features, some of which are unique to meet special needs at City University.

However, the Windows environment has begun to dominate the market because of its user-friendly interface. Subsequently, the Computer Centre wished to identify a suitable Windows-based emulator that provides the same features as PC240. In July 1994, a task force was formed to source, evaluate emulators currently available, and make recommendations. The task force drew various areas of expertise together from within the Computer Centre, such as emulator development, network management and host application development. The task force aimed to identify a Windows-based emulator which supported multi-windows, multi-tasking, window re-sizing, pull-down menus and mouse operation, with minimal modifications required for existing host application systems.

Selection of Candidate Emulators

Numerous software distributors such as Borland, SIS, Tech Pacific, Kenfil, Digital Equipment Corporation (DEC), Jardine Network System (JNS), Attachmate, and Automaton Ltd., were contacted. However, we found that there are very few emulators alone for sale, as most communication software includes terminal emulation as one of many functions.

After consideration, two products were selected for more detailed evaluation, Pathworks VT320/VT382 for Windows and KEAterm VT340. VT320/VT382 are identical text-based Windows emulators, except VT382 supports Chinese. KEAterm VT340 is a graphics terminal emulator for a DEC VT340 terminal.

Testing Criteria

Apart from basic emulator functions such as terminal emulation, key mapping, communication protocol, etc., each candidate was tested against the special features of PC240 listed below. The results are summarised in the next section.
PC 240 Special Features



Before making recommendations, the task force made two assumptions. First, the transition period from the old PC240 to the new Windows-based emulator would be short. Second, only one Windows environment, either English or Chinese Windows, would be chosen as the default. Departments not upgraded from a DOS to a Windows environment may still need to use the DOS-based PC240 as their default emulator.

At this time, no single Windows emulator on the market can support both Chinese and Graphics capabilities. If only one emulator is chosen, one of the two features has to be sacrificed. Since graphics are now used mostly for colour menu displays, most graphic functions would go unused. Consequently the high cost of graphics may not be justified now.

Graphics emulators in general are more expensive, and usually cost double the price of non-graphics emulators. Most host packages that require graphics capabilities have PC versions, and users who want to use this software could be persuaded to use the PC version instead. Another factor in using graphics is the use of colour display for information services host applications such as CityLink, CityData, and PolyLink. If the Client/Server model is adopted in the near future, this factor can be eliminated, or else we will still have to consider this in future.

Another crucial factor is the need to support some Chinese features, such as displaying a portion of Chinese data. For example, the library uses this with Chinese names for authors and titles, and not all the information needs to be displayed in Chinese. The description should remain in English, and this simplifies the Chinese supporting functions.

The third factor is that we should provide consistent user interface whether in an English or Chinese Windows environment. This is a must because it can ease user training and promote the transition from a DOS to Windows-based environment.

A special requirement must be noted here in the selection process. The selection of Chinese internal code is critical since it is very likely that Windows emulators may not explicitly support other Chinese internal codes such as CNS internal code. Even though they may support Chinese in the future, Windows emulators might pass all the input and output controls to Chinese Windows, i.e. Big5 internal code, and may not support other Chinese internal codes such as CNS or CJK codes.

In conclusion, we found that no single Windows emulator on the market can fit all our requirements. Therefore, we will continue to use the existing DOS-based PC240 for the Windows environment until a suitable windows-based emulator is found in the future.

[Issue No. 2]

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Computing Services Centre
City University of Hong Kong

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