System console

The system console, computer console, root console, operator's console, or simply console is the text entry and display device for system administration messages, particularly those from the BIOS or boot loader, the kernel, from the init system and from the system logger. It is a physical device consisting of a keyboard and a screen, and traditionally is a text terminal, but may also be a graphical terminal. System consoles are generalized to computer terminals, which are abstracted respectively by virtual consoles and terminal emulators. Today communication with system consoles is generally done abstractly, via the standard streams (stdin, stdout, and stderr), but there may be system-specific interfaces, for example those used by the system kernel.

History

Prior to the development of alphanumeric CRT system consoles, some computers such as the IBM 1620 had console typewriters and front panels while the very first programmable computer, the Manchester SSEM, used a combination of electromechanical switches and a CRT to provide console functions—the CRT displaying memory contents in binary by mirroring the machine's Williams-Kilburn tube CRT-based RAM.