Chapter 8 NETWORK & COMMUNICATIONS IN I T

 

Networking

                                          

In the early 1960s the first on-line systems were developed. These computers, used for airline reservations, served many terminals connected through various types of communications lines. (A few years earlier, the first such on-line systems were developed for defense applications.) At about the same time, terminals were attached to computers used for time sharing. The major difference between on-line and time-sharing systems is that the former are dedicated to a single application. For example, an airline reservation agent can only make a reservation or inquire about the status of various flights. The agent cannot write a program from the terminal. With time-sharing, the user of the terminal usually does have the ability to write programs.

          The use of on-line systems has expanded rapidly. Today large proportions of new systems have some portion that is on-line, such as data entry, update, and/or inquiry. At the same time, there has been an expansion in the number of alternatives available for establishing communications among computer devices. One has a choice from dial-up phone service to private network using satellites for transmission.