Erik Funkenbusch wrote:
> On Tue, 26 Dec 2006 14:09:58 +0000, Roy Schestowitz wrote:
> > Watch this one image carefully...
> >
> > http://www.asus.com/999/images/products/1299/lockkey.jpg
>
> This is most likely because laptops have odd key layouts, and it may be
> difficult to press ctrl, alt, and del at the same time.
Keep in mind that the selection of these three keys were deliberately
made to make it difficult to do it by accident, because, back in the
days of MS-DOS, CTRL+ALT+DEL was used to physically reboot the system.
NTFS made hard reboots much more dangerous, so the key combinations
were intercepted and used to safely shut down the system.
Later versions of Windows, driven by user suggestions and
reccomendations, extended this "reboot" to allow a controlled reboot,
or just a log off and restart, as well as shutdown. Some of this is
quite similar to the handling of the same key combination on UNIX and
Linux systems. Linux used the key combination as a controlled reboot
when using the text console, and as the Log-out, restart, and shutdown
- going back to some of the earliest Linux distributions when used in
GUI mode.
> FYI, Ctrl-alt-del is used to log in to Windows on corporate networks, and
> it's used to lock the screen. I know you were trying to insinuate using
> ctrl-alt-del to reboot the computer, which hasn't been the case in years.
Very true. Some computers now have a button for this function, similar
to the keyboard you cited. However, the complex key combination is
still used to prevent people from accidentally logging themselves off,
disconnecting from the network, or shutting down the computer when all
they really wanted was to hit a function key.
Ironically, the approach was first used with emacs, which used a meta
key instead of the alt key, but with roughly the same function. For
certain critical functions such as exiting emacs, you had to use a
combination of keys which was difficult to hit accidentally.
Most UNIX and Linux systems didn't even allow a "hard shutdown" almost
from the earliest Unix workstations. This is because a "panic button"
that suddenly shut everything off by cutting the power, would require a
lengthy sanity check to make sure that end-users didn't accidentally
corrupt files or storage allocation.
Having a button to emulate this complex function isn't that new either.
Again, in Emacs, any key combination invoked a function or method
which was the actual job being performed. Users who wanted to
customize their keyboard could bind any key combination to a particular
function or method.
> Welcome to reality, Roy.
Erik is correct. Pressing the ol' "three finger salute" hasn't shut
down or rebooted the computer directly since the early 1990s. In terms
of computer technology, it's almost ancient history.
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