الحاسبات المترابطة - التوصيل الهاتفي .. الحاسبات تعمل

Interconnected computers - Telephone connection .. Computers work

Computers are connected to each other across continents and oceans by fast wire lines or wireless communication links that may use satellites

(The figure shows the idea of ​​the interconnected computer system that connects to each other by fast telephone lines, so that a computer in one city has all the information stored in a computer in another city. The computers also share the operating tasks and features of each of them).

Artificial. Thus, a computer in one city can have the information stored in a computer in another city. Different computers may also share the operating burdens, so the light-duty computer takes on some of the burdens of the computer overloaded with tasks.

The interconnected computer system requires advanced programming and requires the compatibility of the code between computers to be able to communicate with each other.

Ordinary telephone lines are not suitable for fast communication between computers, as the data transfer speed on these lines does not exceed a thousand bits per second. This speed increases with the improvement of the quality of the lines, reaching about forty thousand bits per second for high-frequency cables or wireless communications, and this speed is more suitable for the speed of computer operation.

The speed of communication between computers is of particular importance, as communication wastes valuable computer time and thus reduces the effectiveness of the entire system. It is not enough for communication lines to be able to transmit data quickly, as data is often slow to issue, as is the case, for example, when signals are issued from a touch panel or a typewriter operated by the person using the system. The computer that receives these slow signals wastes a lot of time reading them, especially if there are multiple touch panels that send their signals to the computer. This slowness can be avoided by using small computers to condense signals from a number of slow sources before entering them into the network of large interconnected computers.

For example, let's assume that a typewriter sends a signal consisting of one hundred and twenty characters at a speed of five characters per second, and it takes twenty-five seconds to read it. If it is condensed, it may take six hundred microseconds to read, i.e. an increase in speed of forty thousand times.

Small computers also work in the opposite direction. After the main computer system fulfills the requests directed to it and sends its response at high speed, the small computer slows down the speed of the signals to match the speed of the slow output devices such as printers and the like.

(Signal condensers. The main computer's time is very valuable and should not be wasted reading slow signals. Therefore, a small computer receives these signals and stores them until a sufficient number of them is collected and sends them to the main computer at a very high speed.)