الحاسب الموصل - التوصيل الهاتفي .. الحاسبات تعمل

The connected computer - Telephone connection .. Computers work

Factories and offices may include a few hundred telephone lines carrying digital signals that are transmitted between typewriters, printers and the like. In these cases, an electronic computer can be used to connect these devices to each other. The computer reads the signals, sorts them and sends them to their destinations.

Each feature in digital communication systems is encoded with a single sequence of bits, or binary numbers. The bit with the value of "1" is represented by an electrical pulse lasting twenty milliseconds, while the bit with the value of ". " is devoid of any pulse. Bits are sent in communication lines in succession with a pause pulse interval between adjacent bits. If each feature is represented by ten bits, sending each feature takes two hundred milliseconds, which is equivalent to a speed of five features per second. If the computer is connected to a hundred of these lines, and it takes five microseconds to examine each line to determine whether it carries a pulse or not, the computer examines all the lines every five hundred microseconds, meaning that each bit lasting twenty milliseconds is examined forty times in this manner.

The lines are examined by a special device, known as a multi-channel organizer, so that the computer's valuable time is not wasted on such a routine task. The organizer stores the information it examines until it reaches a certain amount and then sends it to the computer at high speed. The computer stores it in its memo locations in the order in which it is received. Each of these locations stores one feature and the line number on which it was sent. A sorting program collects these features, according to the line numbers and the order of the features in the memo. The original signals are thus organized, and the computer sends each one to its destination according to a code at the beginning of the signal.

Such a system can be expanded to increase its effectiveness in the field of business. Magnetic disks and tapes are added to store the signals. The system can also be linked to the regular commercial telephone and telex network and modified.

This extended system is used by large companies.

Telex signals coming from abroad may be directed to a specific office, according to a special code contained in these signals. The computer prints the text of these communications at the relevant office, where they may be modified or added to before being sent to their destination. The computer can also store many telex or remote printer communications until it is time to send a large amount of data at reduced costs.