How to switch between consoles in Linux

Linux has twelve TTY consoles that can be used to execute commands, restore the system, start Wine or the optional X server. Let's see what these consoles are, where they come from, and how to switch between Linux consoles.

What are TTY consoles?

The abbreviation TTY stands for Teletype or teletype. Back in 1830, special machines called teletype were developed that allowed messages typed on a keyboard to be sent to remote locations. This was a real breakthrough for telegraphy, because even earlier Morse code had been used for this purpose. Messages had to be coded, transmitted, then decoded and printed on paper. Back then, a special coding system was patented that was 89 years ahead of ASCII. Machines using this system had only five keys. The operator had to memorize different combinations for each letter.

In 1963, the ASCI encoding became known, so teletypewriter manufacturers began using it. After the invention of the telephone, the teletype became even more widely used. It became possible to combine many machines into one network. Then from all this came the fax machine in 1980. Computers improved and evolved. At first, instructions were entered using special punched cards, but it soon became clear that this method was extremely inconvenient and time-consuming. Everyone needed a special device to enter instructions and get the result. The best candidate for the place of input/output device was the teletype. It provided everything needed The device was designed to input text, encode it, decode it, and display it. Only now there had to be a computer on the other side, not another teletype.

After that, teletypes began to be used extensively to control PCs and mainframes. Over time, hardware emulators of teletypes, which used not paper for data output, but a CRT, appeared and managed to supplant them with great success. These devices provided more features, such as moving the cursor around the screen, clearing the screen, and editing text. One such virtual teletype was the DEC VT05.

In systems based on the Linux kernel, terminals are a virtual teletype. Only now the teletype is emulated programmatically. Such terminals are called pseudo-teletypes or PTS. Linux provides a pseudo terminal multiplexer that handles connections to all such PTSs. This multiplexer resides in the kernel and is accessible via the /dev/ptmx file. Each of the twelve consoles open by default in Linux is a pseudo teletype device connected to this multiplexer.

Switching between TTY consoles

Each console has its own hotkeys. These are Ctrl+Alt+Fn, where n is the console number from 1 to 12. To open the first console you need to enter Ctrl+Alt+F1, the second console - Ctrl+Alt+F2, the twelfth - Ctrl+Alt+F12 and so on. Open the third console and authorize in it, then look up the pseudo teletype number:

Here the device number is /dev/tty3. Similarly, you can open the sixth console by pressing Ctrl+Alt+F6:

The first console is occupied by the login manager, and the second or seventh by the X server. All the others you can use for your own purposes. Now you know what TTY consoles are, why they are called that, and how to switch between them.