The display adapter, the screen, and the system keyboard are collectively referred to as the physical console, which is controlled by a console driver.
To let you interact with several applications at once, Neutrino permits multiple sessions to be run concurrently by means of virtual consoles. These virtual consoles are usually named /dev/con1, /dev/con2, etc.
When the system starts devc-con or devc-con-hid, it can specify how many virtual consoles to enable by specifying the -n. In a desktop system, the buildfile specifies four consoles when it starts diskboot. For more information, see the description of diskboot in the Controlling How Neutrino Starts chapter. The maximum number of virtual consoles is nine.
The root user can also specify the program, if any, that's initially launched on each console. The terminal-initialization utility (tinit) reads /etc/config/ttys to determine what to launch on the consoles. By default, tinit launches a login command on the first console only, but tinit is "armed" to launch a login on any other console on which you press a key. This means that while console 1 is always available, the other consoles aren't used unless you specifically switch to one of them and press a key.
Each virtual console can be running a different foreground application that uses the entire screen. The keyboard is attached to the virtual console that's currently visible. You can switch from one virtual console to another, and thus from one application to another, by entering these keychords:
| If you want to go to the: | Press: |
|---|---|
| Next active console | Ctrl–Alt–Enter or Ctrl–Alt–+ |
| Previous active console | Ctrl–Alt–− |
You can also jump to a specific console by typing Ctrl–Alt–n, where n is a digit that represents the console number of the virtual console. For instance, to go to /dev/con2 (if available), press Ctrl–Alt–2.
When you terminate the session by typing logout or exit, or by pressing Ctrl–D, the console is once again idle. It doesn't appear when you use any of the cyclical console-switching keychords. The exception is console 1, where the system usually restarts login.
For more information about the console, see devc-con and devc-con-hid in the Utilities Reference, and "Console devices" in the Character I/O chapter of the System Architecture guide.