In Part II (IIASA WP-75-82), a network was described in overall terms which easily handles inter-user communications. This largely ignored, of course, a major function of the network, namely, productive work on large central computing systems (denoted there and here by SYS). The sequence was deliberate. Networks are usually thought of as built around a SYS or set of them, in other words, the network is an adjunct to the central computer(s). The viewpoint in user-oriented networks is just the opposite: central computing systems are facilities available on the network but not indispensable units for all functions of the network. It seemed desirable to establish this viewpoint first.
The above observations, or even a working network as described in Part II, do not diminish the importance of central computers nor make the inherent difficulties of using a variety of them disappear. There will be much to say in subsequent parts of this series about the problems of incompatibility among systems and the confusing variety of conventions, formats and protocols. However, the network scheme of Part II is even more important in dealing with these problems than in handling inter-user communication. Properly used, it can deal fairly effectively with incompatibilities among systems so long as this is necessary, and can be employed to gradually force more standardization in the future
