CICS/VS and its role in Systems Network Architecture
D. J. Eade, Pia Homan, Jeremy Jones · IBM Systems Journal · 1977
When on-line computer terminals were developed, so that input and output operations could be performed remotely from the computer, data could be entered into the system from the point of origin, and results transmitted directly to the place where they were to be used. This mode of operation employed telecommunications, in which terminals were connected to the computer by a communications line as illustrated in Figure 1.