3.8. Information transfer devices. Other peripherals

A device that converts information when it is transmitted between computers over a telephone network is called a modem.

The basis of this process is the conversion of data received from the processor from a digital form into a high-frequency analog signal.

There are modems:

• internal, representing an expansion card, which is installed in one of the free expansion slots on the motherboard;

• external, connected via a special connector to the PC serial port.

One of the most important characteristics of a modem is the maximum data transfer rate that it provides, which is measured in baud (unit of data transfer rate, measured by the number of bits per second). Currently, modems operate at a maximum speed of 28 Kbaud and above.

The fax modem has the functions of receiving and transmitting fax messages. Most often, modern modems are fax modems, and therefore the terms “modem” and “fax modem” are considered synonymous.

Currently, devices are used that can simultaneously transmit data and voice over telephone lines using DSVD technology. The most common modems in Russia are USRobotics, ZyXEL, GVC.

The power supply of the computer is turned off during an emergency. Approximately 80% of computer failures are the result of problems with the power supply system, so uninterruptible power supply (UPS) devices are used to ensure its safety from sudden voltage surges or power cuts.

The uninterruptible power supply contains a voltage regulator, built-in rechargeable batteries and an alternator. In the event of a power failure, this device switches the voltage to itself and for some time provides the computer with energy, which determines the stable operation of the computer. This device is capable of maintaining normal PC power for 3–20 minutes.

Interactive computer system that provides the synthesis of text, graphics, sound, speech and video is called multimedia. A multimedia system is a computer whose main devices meet modern requirements. Such a computer should be equipped with a CD-ROM, sound card, speakers or headphones. The compact disc is one of the main information carriers in multimedia systems; encyclopedias, games and educational programs are written on it. CDs sometimes turn out to be more convenient than books; searching for the necessary information through the use of special software becomes easier and faster.

Audio adapters are used to play, record and process sound, such as sound cards and sound cards. Device data converts computer digital data to analog audio and vice versa; There are several different devices on the sound card that allow you to create a recording studio based on your PC. The main characteristics of audio adapters include: bit width, the number of playback channels (mono or stereo), the synthesis principle used, extensibility and compatibility. The sound quality also depends on the type of sound cards and speakers. Adequate sound quality is provided by any active speakers, and better sound is achieved by connecting an audio card to the input of a home audio system amplifier.