A virtual console (VC) – also known as a virtual terminal (VT) – is a conceptual combination of the keyboard and display for a computer

user interface In the industrial design field of human–computer interaction, a user interface (UI) is the space where interactions between humans and machines occur. The goal of this interaction is to allow effective operation and control of the machine f ...

. It is a feature of some

Unix-like A Unix-like (sometimes referred to as UN*X or *nix) operating system is one that behaves in a manner similar to a Unix system, although not necessarily conforming to or being certified to any version of the Single UNIX Specification. A Unix-li ...

operating system An operating system (OS) is system software that manages computer hardware, software resources, and provides common services for computer programs. Time-sharing operating systems schedule tasks for efficient use of the system and may also in ...

s such as

Linux Linux ( or ) is a family of open-source Unix-like operating systems based on the Linux kernel, an operating system kernel first released on September 17, 1991, by Linus Torvalds. Linux is typically packaged as a Linux distribution, which ...

BSD The Berkeley Software Distribution or Berkeley Standard Distribution (BSD) is a discontinued operating system based on Research Unix, developed and distributed by the Computer Systems Research Group (CSRG) at the University of California, Berk ...

illumos Illumos (stylized as illumos) is a partly free and open-source Unix operating system. It is based on OpenSolaris, which was based on System V Release 4 (SVR4) and the Berkeley Software Distribution (BSD). Illumos comprises a kernel, device d ...

, UnixWare, and

macOS macOS (; previously OS X and originally Mac OS X) is a Unix operating system developed and marketed by Apple Inc. since 2001. It is the primary operating system for Apple's Mac computers. Within the market of desktop and lapt ...

in which the

system console One meaning of 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 ...

of the computer can be used to switch between multiple virtual consoles to access unrelated user interfaces. Virtual consoles date back at least to

Xenix Xenix is a discontinued version of the Unix operating system for various microcomputer platforms, licensed by Microsoft from AT&T Corporation in the late 1970s. The Santa Cruz Operation (SCO) later acquired exclusive rights to the software, and ...

United States Patent 4945468 lists Xenix as prior art in this area. and

Concurrent CP/M MP/M (Multi-Programming Monitor Control Program) is a discontinued multi-user version of the CP/M operating system, created by Digital Research developer Tom Rolander in 1979. It allowed multiple users to connect to a single computer, each u ...

in the 1980s. In the

Linux console The Linux console is a system console internal to the Linux kernel. A system console is the device which receives all kernel messages and warnings and which allows logins in single user mode. The Linux console provides a way for the kernel and ...

and other platforms, usually the first six virtual consoles provide a

text terminal A computer terminal is an electronic or electromechanical hardware device that can be used for entering data into, and transcribing data from, a computer or a computing system. The teletype was an example of an early-day hard-copy terminal and ...

with a login prompt to a

Unix shell A Unix shell is a command-line Interpreter (computing), interpreter or shell (computing), shell that provides a command line user interface for Unix-like operating systems. The shell is both an interactive command language and a scripting langua ...

. The graphical

X Window System The X Window System (X11, or simply X) is a windowing system for bitmap displays, common on Unix-like operating systems. X provides the basic framework for a GUI environment: drawing and moving windows on the display device and interacting wit ...

traditionally starts in the seventh virtual console (tty7), although this is configuration dependent. In Linux, the user switches between them by pressing the

Alt key The Alt key (pronounced or ) on a computer keyboard is used to change (alternate) the function of other pressed keys. Thus, the Alt key is a modifier key, used in a similar fashion to the Shift key. For example, simply pressing ''A'' will t ...

combined with a

function key A function key is a key on a computer or terminal keyboard that can be programmed so as to cause an operating system command interpreter or application program to perform certain actions, a form of soft key. On some keyboards/computers, function ...

– for example + to access the virtual console number 1. + changes to the previous virtual console and + to the next virtual console. To switch from the X Window System or a

Wayland compositor Wayland is a communication protocol that specifies the communication between a display server and its clients, as well as a C library implementation of that protocol. A display server using the Wayland protocol is called a '' Wayland composito ...

, + + works. (Note that users can redefine these default key combinations.) If several sessions of the X Window System are required to run in parallel, such as in the case of

fast user switching Fast user switching is a feature of a multi-user operating system which allows users to switch between user accounts without quitting applications and logging out. In Linux The Linux kernel's VT subsystem dates back to 1993 and does not under ...

or when debugging X programs on a separate X server, each X session usually runs in a separate virtual console.

Implementation details

Unix systems

Unix

workstation A workstation is a special computer designed for technical or scientific applications. Intended primarily to be used by a single user, they are commonly connected to a local area network and run multi-user operating systems. The term ''workstat ...

s, such as those manufactured by

Sun The Sun is the star at the center of the Solar System. It is a nearly perfect ball of hot plasma, heated to incandescence by nuclear fusion reactions in its core. The Sun radiates this energy mainly as light, ultraviolet, and infrared radi ...

Silicon Graphics Silicon Graphics, Inc. (stylized as SiliconGraphics before 1999, later rebranded SGI, historically known as Silicon Graphics Computer Systems or SGCS) was an American high-performance computing manufacturer, producing computer hardware and sof ...

, did not include virtual consoles. The only purpose of a console would be to fix the system so that the graphical environment could start. Sun Niagara-based servers running

virtualization In computing, virtualization or virtualisation (sometimes abbreviated v12n, a numeronym) is the act of creating a virtual (rather than actual) version of something at the same abstraction level, including virtual computer hardware platforms, stor ...

with

Logical Domains Logic is the study of correct reasoning. It includes both formal and informal logic. Formal logic is the science of deductively valid inferences or of logical truths. It is a formal science investigating how conclusions follow from premise ...

get virtual console services from the ''Control domain''.

Notes

References

* FreeBSD Handbook, chapte
3.2 Virtual Consoles and Terminals

External links

Linux command chvt to switch vt from cmdline

XENIX -- Microsoft's Short-lived Love Affair with Unix
{{DEFAULTSORT:Virtual Console (Pc) Computer terminals Terminal multiplexers User interfaces

Implementation details

Unix systems

See also

Notes

References

External links