Slashdot Mirror
Ctrl-Alt-Del Inventor To Retire From IBM
wherley writes "AP reports that IBM'er David Bradley, who came up with the (in)famous Ctrl-Alt-Delete key combination, is retiring. The article mentions: 'At a 20-year celebration for the IBM PC, Bradley was on a panel with Microsoft founder Bill Gates and other tech icons. The discussion turned to the keys. 'I may have invented it, but Bill made it famous,' Bradley said. Gates didn't laugh. The key combination also is used when software, such as Microsoft's Windows operating system, fails'." We featured a story on Bradley a few months back.
I RTFA and here is why he chose that...He chose those keys specifically as it's not a key sequence that can be struck by accident. This straight from the previous slashdot article.
For one thing, it's damned near impossible to hit those three keys simultaneously on accident. Other than that, there's nothing special about the combination.
On the Mac, the sequence is Command-Option-Escape.
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the strongest word is still the word "free"
"Bradley chose the control and alt keys because he needed two shift keys to make the operation work, and he chose the delete key because it was on the opposite side of the keyboard. He didn't want people to hit control-alt-delete by accident."
link the article mentioned on slashdot earlier
-- If I were a fish, I'd be wet
I don't remember where I got it from, but I have an ASF of the movie. Decided to throw it up on my CMU webspace so lets see if we can /. andrew =)
CtrlAltDel.asf
Oh, the movie doesn't start 15 seconds for some reason. Wasn't me.
'I may have invented it, but Bill made it famous,' Bradley said.
Note that Bradley claimed to be referring to the NT logon procedure. Full quote is from this video.
Gates didn't laugh.
For some reason I thought Gates had a sense of humor.
Too bad he can't even laugh at himself.
(Anyone else get bit by the Linux will reboot with CRTL-ALT-DEL, but Win NT 4-XP will ask for Logon? I've rebooted machines on KVM switches by accident many a time, especially if I can't remap the salute like I usually do!)
/etc/inittab
You mentioned remapping the salute, but it was vague on which OS you meant, so I thought I'd just clarify.
You can change the program that is run when you press CTL-ALT-DEL on Linux by editing
...that sequence was chosen for security. From http://www.xfocus.net/articles/200103/winnt.pdf :
"After the SAS [Security Attention Sequence] is triggered in Windows NT, all user-mode programs stop. No program can trap the SAS sequence; it is the sole property of the security subsystem. If a user presses Ctrl+Alt+Del, he can be assured that his information is secure."
Any key generates an interrupt request -- MS chose Ctrl+Alt+Delete because it was/is considered "special" by PC users.
From left to right, what order do you see the keys in?
It's possible for this to have been disabled in the BIOS, however the only PCs I've ever seen with no support for this at all are some old low spec Compaqs.
Shoot Pixels, Not People!
Macs have another great keyboard combo: Command-Option-Escape! On old-school macs it would generally not help, but on OS X it's the friendliest GUI to kill -9 I have ever seen.
:)
That also reminds me, on OS 9, you could press command-power, and escape to a prompt. The only command I know of was 'go', which would take you to the Finder. Great on the older installs of At Ease
Does CMD-Power work on OS X? Here goes....
PtrScrn - Used to be used to send the current screen of characters to your printer. Now copies the equivilent of the windows framebuffer to the clipboard.
SysRq - Not sure on this one, never used it, - possibly from mainframe terminal keyboards.
Pause - Paused the exeuction of the running program (remember: this was before OS's capable of multitasking), still used occasionally in games.
Break - killed the current program, well at least it was supposed to. You had to add a CTRL to it when pressing. I believe it originally came from when mainframe terminals were popular.
#!/bin/csh cat $0
it can't be handled by any input APIs (Win32/DirectInput)... it gets handled directly by the keyboard driver.
This kind of keystroke is called SAK (Secure Attention Key), as it's not specific to Windows NT.
SAK is an keystroke (or other event, for example sending "break" on a Sun serial port) that the OS guarantees only the Operating System can ever handle.
THIS THING CAN TURN ON A DIME, MACROSSZERO STYLE ALSO FUCK BETA, ~NYORON
Hmmm, google is your friend. This page covers all three keys, but here is a little description of each:
The main intent of the Scroll Lock key was to allow scrolling of screen text up, down and presumably sideways using the arrow keys in the days before large displays and graphical scroll bars. You can see where this might have been handy in the DOS era, when screen output typically was limited to 80 characters wide by 25 rows deep. For some types of programs, spreadsheets being the obvious example, it's still handy now.
In layman's terms [...], "You can make a multitasking program manager monitor a specific location in your computer's hardware so it can do something cool, such as letting the user switch tasks, when the SysReq key is pressed." As it turned out, the developers of Windows didn't use SysReq when implementing task switching. Some new keyboards no longer feature this key, and its days seem numbered.
The Pause/Break key was used in the DOS command line environment to pause scrolling of text on the screen, which could, depending on the program and its method of text output to the screen, have the effect of pausing program execution.
Cameron King
Look at an original 84 key keyboard (which is what the original PC shipped with), Control and Alt weren't duplicated on the right side of the keyboard (for that matter, control was where we expect capslock now). It would have been really hard to hit it with a single hand.
Ctrl+Shift+Esc will bring up the task manager directly without having to go through the security box.
here is another short article about this.
To actually change the key sequences, change what gets mapped to 'Boot' in your kernel keymaps file. On Debian, this is /etc/console/boottime.kmap.gz; I'm not sure about others.
to pause a booting system so I can read/write down useful info like bios versions. Just hit enter when your done and away you go.
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Umwhat? In what way is ctrl-alt-delete a hardware interrupt? It's branched out of the standard key handler earlier than other keys, and generates a (different) software interrupt, if that's what you meant... but it sure ain't what you said.
I've had this sig for three days.
The Magic SysRq key makes a Request to the Linux System -- Alt + SysRq + (on x86)
/usr/src/linux/Documentation/sysrq.txt
For more details, study
Very useful. Far more convenient than pressing some chord that brings up a GUI screen with buttons to press. The framebuffer may be corrupted, for instance, or the mouse non-responsive, or the GUI server frozen, etc.
The real reason it that no application can accept that keypress, so you know when you press it, it goes directly to the operating system. Thus it was impossible for anyone to write a program to make a login screen appear when you typed in that combination, so it was impossible to spoof the login program (as can happen on Unix boxes where the login is a simple program). It's a security thing, and it was actually a good idea (this was back when Windows "for Workgroups" was a good looking VMS as opposed to an unnaturally tweaked OS buried under a massive compatibility layer)
The full handler was: int 9, al = scan code -> calls kb translator: int 15, ah = 0x4f, al = scan code, on return al = modified scan code. The resulting scan code is looked up and dealt with as a special case or passed on up to higher level software.
Hooking this interrupt was a first dos asm program for lots of us in the old days - I haven't poked around at that level in a while so I don't know if NT had some sort of scheme to prevent those sorts of hijinks, and if so why any other key sequence would not have worked just as well.
Scrl Lock works the same in Excel as it did in the good old days on 1-2-3.
PrtScr, in DOS days, sent the contents of the (text mode) screen to the printer. In Windows, it copies the contents of the display to clipboard (some games also map this to internal screenshot command, saving a screenshot to file). In Linux, um, it can be bound to whatever command you need in Hotkeys application or its ilk. I use it to save a screenshot to /tmp/sshot.png.
SysRQ was supposed to be a funky command switching / task management key in any of the cool future PC operating systems. Nobody bothered, except perhaps the Linux developers who envisioned "Magic SysRQ key", useful for tasks like rebooting the computer cleanly if X11 or something has once again messed up the console completely.
Scroll Lock is used to switch the cursor keys to "scroll mode" in modern apps. Or, to pause terminal output in Linux. Or something similar. Pause/Break is probably so obscure that even the inventors didn't yet know what the heck those were supposed to be used for - "future expansion" in case something needed to be paused or broken, more likely.
in
Many HP calculators have their own version of ctrl-alt-del, which can be used to reset the calculator to a known state, as it was when shipped from the factory. Try pressing and holding the key in the lower-left corner, and then simultaneously press the key in the top-left corner and the key in the top-right corner.
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A lot of time, if the thing's completely locked, that's not responsive either, as that switch connects only to the MOBO. I prefer an actual *switch* that goes only to the power supply.
I've seen computers that could only be reset by unplugging the damned things. Newer ones, too.
"Bill did not laugh." Oh, come on. You make it sound like he was pissed. If you've seen the video, he smiles light-heartedly at him and takes the joke.
He's not some evil guy--he's human like everyone and can take criticism in good fun from colleagues.
16 bit windows did the same, it brought up a task list that wasnt always on top.. so xp is just going back to the win3.x style
Actually, in 16-bit Windows (Windows 3.1), pushing CTRL-ALT-DEL would bring up a bluescreen. If an application had frozen it would say something like "(Application name) is not responding...press ENTER to terminate the application, push ESC to return to Windows and wait, or push CTRL-ALT-DEL again to restart your computer." The task list was invoked with CTRL-ESC.
Bill getting slammed about the three-fingered salute
Bill at the Windows 98 premiere watching the demo blue screen
I'd almost feel sorry for the guy, but he's worth more than most countries and can do whatever the hell he wants.