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The Guy Responsible For Ctrl-Alt-Del
Gannett News is running a story about David Bradley, the IBM engineer who, in 1980, coined Ctrl-Alt-Del. Interestingly, he meant for it to remain a developer-only tool, not something for end users, and certainly not to have Windows users change their passwords or logoff. He also says he chose those keys specifically as it's not a key sequence that can be struck by accident.
Ctrl-Alt-Del is the only key combination on your computer that has its own hardware interrupt (similar to Ctrl-Open Apple/Closed Apple-Reset on Macs). Again, this was to prevent interception in real mode, however protected mode changes all rules.
Try not. Do or do not, there is no try.
-- Dr. Spock, stardate 2822-3.
Ok, so he chose Ctrl-Alt-Del to do a warm boot. Maybe he could have chose alt-x-y-5-* or ctrl-alt-f1-f2-f7........ Why's this being written about as if it is some innovative rocketery? Someone had a computer system. They wanted to be able to do a warm boot fast. Therefore they made a key-sequence to allow it. And this is a story . . .
Anybody wanna fill in on the details here?
...just my 2 gil.
I prefer alt-control-delete. More alphabetical, and the mono-syllable alt isn't sandwhiched between multi-syllable words.
The use of ctrl-alt-del to login to or unlock windows NT, and to change the password was one of the things Windows NT did right. On x86 hardware ctrl-alt-del generates a harware interrupt. So it always traps into the OS. This helps prevent trojan login screens and such.
I can write an app that looks just like the NT login that will e-mail me all passwords and present the user with an 'incorrect password' dialog. And maybe make it exit so the user next sees the nornal login tool to make it less suspicious. However, I can't write an app to trap the ctrl-alt-del, so it doesn't work.
...but there's a reason why Windoze uses that for logging in. That is, that key combo cannot be intercepted by applications thus making it impossible to create infamous fake logins for grabbing user credentials mere looks-like-login-screen. Naturally such preventive measures could've been done a bit more elegantly than just using ctrl-alt-del to log in, but still, it's a very windowsy way of overcoming obstacles.
In many unix systems however, there are little or no protection for fake-login local attacks, eventhough preventive measures would be quite easy to implement using some key combo deemed ungrabbable by user software (little like say ctrl-alt-backspace is in X). It's all too easy to display a xdm/gdm look-a-like screen on university/public-office displays and grab logins and then display some sort of segfault crap an logout back to the real xdm/gdm. Average (l)user hardly takes much of a notice.
1 Earth is warming, 2 It's us, 3 it's royally bad, 4 we need to take action NOW
I once worked at a help desk. One call I remember is a man who, after my suggestion he should press "control alt del" went silent for a moment, then told me he only had one hand.
;-)
(It's sad to see that an option that was originally meant for engineers, made it all up to the login screen of an operating system. Well, maybe Larry presses the "eject" button to start his plane, what do we know?
my other sig is a 500 page novel
I have had Dr. Bradley for several classes at NCSU, he is a good instructor and mostly just jokes about his part in creating the first IBM PC. His famous quote is "I may have created ctrl-alt-delete, but it took Bill Gates to make it famous." I wish there were more guys like Bradley that took time to come back to the classroom and share there valuable experience with the next generation of engineers. Thanks Dr. Bradley.
Your reasoning does not apply to Windows NT4, as DirectX allows application to intercept any key combination, including the three-finger salute.
The same goes for remote desktop applications such as "PC anywhere" etc.
So it really is a major annoyance and serves no purpose.
The later use came about because it is the only sequence that cannot be hijacked
I love that security message from MS. I'm still waiting for someone to make a bootable linux CD (or hell, a DOS disk) that displays the same screen, looking like win2k and harvesting logins. It's not that hard to intercept ctrl-alt-del. I wonder if you could do it by messing with the keyboard drivers too. If you can change the signal the OS sees when ctrl-alt-del is pressed, you could intercept the interupt w/out resorting to using another OS.
t'nera semordnilap
On the video, someone made a comment about Ctrl-Alt-Del being a life saver as an easy way to reboot systems after a crash (back when the blue screen stayed up by default). His response was "I just coded the Ctrl-Alt-Del sequence. Bill Gates made it famous." The implication wasn't intentional, but the look on Bill's face was priceless.
Buy the President
CTRL-ALT-DEL is can never, ever be trapped by an application
I mapped it to something like ``xset s activate'' on my Linux box. I kinda laugh every time I hit it just because I think it's funny that I mapped my lock to a key combination that ``can't be trapped by an application.''
-- The world is watching America, and America is watching TV.
I have never came across more unergonomic key sequence than Control-Shift-Esc.
Left thumb on Control-Shift, left index or middle finger on Esc. Although I suppose that might be hard if you have small hands or a strangely arranged keyboard.
The intertec Superbrains and Compustars had a pair of RED keys - one at each end of the keyboard. You had to depress BOTH of them to get a reboot. I was working on these machines when the IBM PC hit the market, as one of my then bosses went to the show where they were announced.
I think those machines had been around for 3 or 4 years by then. I know they pre date 1981 when I was working on them, as the Compustar was the "new and improved" version of the Superbrain.
And these machines were probably copying someone else as well, but we will never know who, because Intertec went the way of the dinosaur....
Here's a webcomic that's just over a year old that some of you might like, it is called ctrl+alt+del :)
http://ctrlaltdel-online.com/
The main characters are a few crazy gamers, and a linux guy who has a live-in penguin named Ted. Hillarity ensues.
--------
It's OK to be social, just don't tell anyone about it.
Why do I have the impression history's being re-written, here?
IIRC, (both the article and, huh, "Real Life") the "Three Finger Salute" came to be at the M$' request, as they did not want to see a reset switch on the original IBM PC. Real, physical reset switches already existed on microcomputers and could be used to take control of a machine without purging the memory (well, not entirely) and see the binary code/data structures loaded in RAM, this for reverse-engineering... or just to save your butt when sh*t hit the fan.
I vaguely remember having to reset a TRS-80 Model II (? or IV?) before it created more damage (sp?) and using a debugger (the one with the "spinning slash" in the top-right corner, IMSMR) to examine the contents of RAM to find some just-entered data to jot it down and re-enter it when we restarted the accounting application.
This was the kind of thing that scared the hell out of M$ because they thought everyone was out to steal their s/w. So a soft switch like the TFS could invoke some memory-wipping routine, foiling the techies' efforts to have a better understanding of what was going on.
CTRL-ALT-DEL also switches to another desktop that programs are not allowed to modify in any way (Yes, Windows has multiple desktops, see recent Dr. Dobbs article for more info).
> Yeah, but who made the Mac shortcut? They have two:
// days.
// and //+ i believe this was used by the basic addon card (Each machine came with one ver of basic in it, and the other version on an addon card, depending which modal you got. the //+ had more ram too)
;)
//GS. That key combo was added to get into the systems control panel (There generally wasnt an OS)
//gs just wanted something similar and familiar but different (escape vs reset), and the macs just continued using them because apple users were used to it.
>
> Command-Option-Escape is Force Quit...
> Control-Command-Power is Restart
Those are actually left over from the Apple
The apple//'s had two 'alternate' keys, open-apple and closed-apple (Pictures of either an apples outlike, or a solid apple)
There was also a hardware reset button.
There was no alt, but there was control and shift (standard ASCII practice at the time)
The reset key was hard wired into the interupt controller, but it performed a soft-reset used alone, and by default the jump register was not set so the key didnt do anything.
In the
Technically speaking, the two apple keys were not handled by the keyboard controller, but by the joystick controller.
As a matter of fact, open apple and closed apple were button 1 and 2 on the first joystick. So technically one could reboot with a joystick-button, control, reset as well
Just open-apple and reset caused a soft-reset signal to the cpu. this signal told the cpu to simply jump to a memory location ($FFFD if memory serves) and not to reset any other states or registers. This was used to 'break' programs run that didnt want to give it up easily and trapped control-C and the like.
In the three bytes there you had a jump command, and the next two bytes are the address where.
Then they added the 3rd key, control, which is actually the only key of the three that comes through the keyboard controller.
So there is one direct interpt key (reset), an apple key (joystick), and control key (keyboard) that all three caused the cpu to reset the counters and registers so the chip would have to reboot from scratch.
Later, closed apple was removed, and open-apple was renamed 'command' and given a stupid clover looking icon. Nowadays open-apple/command is also labeled as 'alt', and in USB keyboards actually sends the same keyboard code.
The open-apple,control,escape was actually from the Apple
On the apple// it was a hardware reason. the
(Ahh the wasted brain memory I have used up on that subject heh)
...worked around the issue on the 80286 that there was no way to switch back to "real" (16-bit segmented addressing) mode from "protected" mode.
t ed +mode
http://www.hyperdictionary.com/computing/protec
IIRC, the IBM PC AT (which first used the '286 and implemented protected mode operations) would send a signal to the keyboard, which in turn reset the CPU (the only way to get back to real mode) and somehow got the machine to proceed with what it was doing.
After learning about that, I switched to the Mac and never looked back (even if the 68000 did have its own quirks...)
I have been Dr. Bradley's Teaching Assistant http://courses.ncsu.edu/ece/ since January, and it has been a pleasure working for him. He is really a motivation. Down to earth and sharp, thats what makes him different from other famous people. Even as an instructor, he likes to maintain tasteful interaction with his students and the students love him too.
:-)
You have to see his "I love me" collection to really appreciate him though
-es
In Windows NT, applications do not have access to the vector table (or at least they aren't supposed to, heh heh) so they cannot change the keyboard interrupt handling routine, and they cannot change the behavior of ctrl-alt-del. However, in DOS, any program can indeed alter the vector table, and so you can mask ctrl-alt-del. So actually, it was pretty pointless in terms of protecting you from a Windows NT lookalike written in DOS or Windows 3.1[1], but it will protect you from a program running on Windows NT which does the same thing. In order to change the OS, you will need physical access to the machine in almost all cases, and so this is considered to be a useful security measure.
"You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
Just imagine how much in royalties this guy could have made if he had developed that nowadays with our patent frenzy attitude!
I'm pretty sure the implementation executed by Ctrl-Alt-Del is covered in IBM patent #4,768,149, filed in August 1985. This patent describes the basic intentions and implementation of the original Ctrl-Alt-Del keystroke.
Wow, someone just claims something and it's instantly "+5" because it's anti-Windows.
It still needs reboots.
No, it doesn't. This is the point in which I mention my machine runs every day without being rebooted. We just leave our machines on. Only when we patch do we reboot, but that's not often since we're behind a firewall anyway.
It acts better once rebooted.
I've noticed no difference whatsoever.
In generalm Win2k and XP get alower the longer they run, and start experiencing problems like randomized icon images, windows that don't redraw, loss of fonts, etc.
Complete bullshit. I have never experienced "randomized icon images, loss of fonts, etc." and neither have any of my co-workers or anyone else I know. XP and 2k don't just magically get slower as you use it and start randomizing icons. If so, it's a memory leak in some app you're using. If you're losing fonts and icons, that is an issue you need to take care of. Windows has nothing to do with it.
A reboot fixes all. When my Win2k laptop gets to where it's using >350MB of RAM, and I've closed all the apps, it's asking to be rebooted.
Sounds like a severe configuration error on your end, either in hardware or software. Want to know how much memory Windows XP is using on my laptop right now with Dreamweaver MX 2004, Publisher 2003, Opera, and Voyager2 open? 132MB.
Your problem is not a common problem at all. Fix it and stop blaming Windows.
"Sufferin' succotash."
is written. It's a revelation to some but people like Tolkein, King, etc often don't really know, beyond the inital premise, what's going to happen in their stories. In Stephen King's "On Writing" he claims a creative process that is more discovery than anything else. There isn't an all-encompassing outline drafted ahead of time. He starts out with an idea like "what if there was a cemetary that brought people back to life" and proceeds from there. He likens it to simply catching the story on paper as it falls out of his head. I don't know if this is what Tolkein was talking about but it works for alot of people.
The cleanest setup for this was on the Apollo Domain, which had a "normal/service" keyswitch. In normal mode, the system booted up with no intervention messages and no delays. In service mode, the machine booted up into a menu of service options. But that was before ordinary people knew about computers.
a quick check seems to imply that the facts are OK, so this might really be Dave Bradley.
Joachim
People don't write Manifestos any more -- what's going on in this world? [Frank Zappa]