Control-Alt-Delete

Users of personal computers and other computer systems call in the IT jargon with clip handle, monkey grip or even (because of the strange-looking hands Attitude) Vulture 's Claw ( short claw) Ctrl Alt Del (Ctrl Alt Del ), with the finished is not responding ( crashed ) programs or the computer can be started hot new. This key combination can be reached usually only two hands to impede accidental operation. As a rule, an administrative function of the operating system or the graphical user interface is invoked by the key combination that helps to correct the interference.

MS- DOS and Windows

The term developed from the combination Ctrl Alt Del for the first time on IBM PCs under MS -DOS. However, this is not a command from DOS, but a tightly integrated in the computer BIOS command. Originally, David Bradley, a computer science engineer, for it provided the Ctrl Alt Esc, but this could be too easily pressed accidentally, such as when you slip left of the keypad with your hand. The Ctrl Alt Del was chosen because it can hardly be accidentally press. On older keyboards, the left had only Ctrl and Alt keys, they could only be triggered with two hands; on newer keyboards, the same function with Ctrl AltGr Del also be triggered with one hand.

The exact function of Ctrl Alt Del is operating system dependent. Under MS- DOS and OS / 2, the computer will restart without prompting, with OS / 2 before we got a few cleanups. Since Windows NT, the Ctrl Alt Del is called the SAS (Secure Attention Sequence ) and an interrupt is triggered, today the term is used more generally. According to Microsoft, this key combination can be emulated by any application on " hardware level ", also remote maintenance programs such as VNC send this command only as emulated keyboard command to the operating system, an immediate reset is not possible here.

This three-button combination has long been integrated into the PC's BIOS, it is a software command that is ' built into the PC. So you can also have a PC that is " stuck " in the boot sequence, bring to a "soft" reset, trigger a "warm start ". An operating system on an IBM - compatible PC must intercept these BIOS command so that a reset is executed immediately. Operating systems that do not overwrite the Standardbiosfunktion ( such as MS -DOS), can not.

In newer versions of Windows, the key combination is used to change an extensive menu with commands to log off or shut down the computer, password, access blocking the station, in which the Task Manager can be opened. However, this is directly called by Ctrl Shift Esc. With it, you can stop computer programs, start and monitor. Furthermore, it offers the opportunity to view utilization of the processor and memory, and individual tasks to processes and thus due to open files. The operating system can be shut down via the task manager, reboot or switch to standby mode.

Overview:

• Under DOS, this key combination is recognized by the BIOS, which starts a function that restarts the computer. It is possible to trap this key combination, which was of some disk cache programs (eg Smart Drive) done to flush the write cache before the computer is restarted.
• Under Windows 95, Windows 98 and Windows ME is a simple task manager is called, pressed again, a restart occurs.
• On Windows NT and Windows 2000, the dialog box " Security " is displayed.
• In Windows XP, the Task Manager is displayed if the Welcome screen is enabled, otherwise the dialog box " Windows Security" appears.
• On Windows Vista and Windows 7, the combination opens a Auswählseite, similar to XP with disabled welcome page. The Task Manager then you open directly with Ctrl Shift Esc ( like we do with Windows 2000 and XP).
• With Windows 8 a selection page is displayed, which provides the ways to access the Task Manager, log off, switch users or enter the lock screen. Furthermore, the regular Button, a language and the Ease of Access Center is still displayed.

IRIX

Under IRIX the monkey grip Ctrl Shift F12 / reads (with / on the numeric keypad ).

Linux

Linux has several monkeys handles. In addition to Ctrl Alt Del, which can directly trigger a reboot in text mode consoles (depending on required for this purpose ctrlaltdel entry in the / etc / inittab ), there are combinations with the so-called Magic SysRq key. These are selected with SysRq appropriate key ( on English-language keyboards SysRq appropriate key ), where S - Abf, except on some notebooks, an alternative assignment of the pushbutton (English PrintScrn ), and although Alt Print Screen. A clean as possible restart a crashed Linux machine is triggered by holding down Alt Print and during which the sequentially following pressing the R, E, I, S, U, B buttons. Instead Alt and Alt Gr can be used, which is often more feasible with one hand.

On Linux, a signal to the init process is sent via Ctrl Alt Del, which then performs a configured command (eg Reboot the computer ). However, a local X server intercepts this key combination, and allows you to call your own functions. This is used by environments such as KDE or GNOME to display a configurable dialog box that the "look and feel " of MS Windows is quite similar and partially beyond capabilities.

X Window System

Under the cross-platform GUI X Window System also has a number of monkeys handles available. The most famous of which is potentially Ctrl Alt ← (backspace ), the graphical user interface and all its running processes terminated immediately ( kills ). If a display manager is active, the graphical interface is restarted by pressing the key combination from the display manager and then typically displays a new login screen. In some systems, this key combination is disabled; it is controlled by the options DontZap and Handle Special Keys in the ServerFlags section of / etc/X11/xorg.conf. Sometimes ( eg OpenSUSE ), the X server is configured to first hear a long beep as a warning and the X server only when a new Ctrl Alt Backspace is terminated.

To cancel that are stuck processes, either the key combination Ctrl Alt Esc followed by clicking on the appropriate window used (which calls the program xkill on ) or the key combination Ctrl Esc, which invokes a window similar to the "Processes" tab of the Windows Task Manager.

This behavior is completely dependent on the window manager used and can vary greatly under certain circumstances. Some window managers also no "emergency " key combinations available, so often F1 or F2 to resort to F6 to change console with Ctrl Alt.

Macintosh

For Macintosh computers, the keyboard shortcut to end a single program: ⌘ (Command ) ⌥ ( Option key) esc.

To restart: Press simultaneously " Power Button " ( remote key with showing to the left triangle) ⌘ ctrl and, with newer Macintosh computers ( without power button on the keyboard ) ctrl ⌘ and Eject.

Delete Parameter RAM: After switching the computer P R down ⌘ ⌥ until the startup sound has sounded for the third time, then release buttons.

Apple II

The computers of the earlier Apple II series (not to be confused with the Macintosh II) have a reset button on the keyboard, which resets the processor directly. For all Apple II models except the rare original model reset causes but only about anything at all, if at the same time Ctrl is held down (for the Apple II , this is selectable by a slide switch on the computer inside the keyboard card, but turned on by default ). This simple reset by the key combination Ctrl reset can be intercepted from the Apple II programs, it is already captured by the standard firmware of the computer and causes in this case only one stop of any running program and a reset of the screen in the text mode; the Apple II can therefore be started only by switching off and on again from scratch. From model Apple IIe, there is also the not catchable Ctrl Empty apple Reset (or Ctrl ⌘ reset on the Apple IIGS and the Apple IIc ) that triggers a reboot without asking. The key combination Ctrl Completed Apple Reset ( or Ctrl ⌥ Reset ), however, causes a self-test of the system. On the Apple IIGS that key is used as a reset button, which is used on the Macintosh as a " power button " - it is usually marked with a left-pointing triangle.

Amiga

On Amiga computers consists of the Apes handle the key combination Ctrl Amiga Amiga. This has already been recognized by the built- in keyboard microcontroller; this acts directly on the reset signal from the computer. Depending on the embodiment, the microcontroller has a dedicated connection to the reset signal (e.g., A500 ), or it generates a signal sequence otherwise used on the data connection to the computer, which is detected by circuitry in the computer, which generates a reset signal ( eg Amiga 1000). This need not be part of the operating system to run; interception by the software is only possible by hooking into the boot process.

Commodore 8- bit computers

When VC 20, C64 and C128, the Restore button, which is connected as a single button directly to the CPU handles, an NMI (non -maskable interrupt) from which is normally intercepted by the operating system or application and therefore shows no visible effect. But if while holding Restore the Run / Stop button is held down, the operating system performs a kind of soft reset, holding a running program (but leaves it in memory ), the sound and the video chip, and the other interface modules to the startup settings resets, the screen clears and brings the user back to the BASIC prompt. This soft reset but is only effective in non abgestürztem processor and still reasonably intact memory contents. On the old C64 variant in brown " bread box " housing Restore works because of a wrong -sized capacitor only when the key is "beaten" very short and strong; on newer C64 and on the other Commodores they can also be pressed completely normal.

Because Restore fails to make the desired in many cases, many users a hardware reset button to build an addition or connect it externally to the user port or the serial bus (CBM - bus, 6 - pin DIN socket). Since over the serial bus, for example, the floppy drive or the printer is connected, these devices will also be reset. At the factory later Commodore models had a side-mounted hardware reset button. Even the press of such a hardware reset button can be intercepted by appropriately designed programs, many copy-protected games delete in this case, for example, the store to complicate the creation of a " bootleg ".

AS/400, iSeries, System i

In a 5250 terminal session in the OS/400 operating system ( ie from version V5R3 i5/OS) can be displayed via the monkey handle Shift SysRq data enable the system request menu. There is then the option to cancel the previous program to open an alternative job (meeting ) or completely log off the currently ongoing dialogue job from the system. The terminal session is only the client, the program runs on the server. The SysRq key is different from the classic PC keyboard, an extra button on the top left, because the keyboards for the AS/400 have 122 keys.