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.

Comments

Another interesting fact:

[Sheetrock]

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.

Was it first?

[Shamashmuddamiq]

...or was the Apple ]['s openapple-control-reset first? I know that the Apple ][ came out in 1977, but I'm not sure if it had implemented the three-key sequence yet or if it had borrowed that idea from the alt-ctrl-delete that was noted here.

Anybody wanna fill in on the details here?

Re:Was it first?

[Hugh George Asm]

..or was the Apple ]['s openapple-control-reset first? I know that the Apple ][ came out in 1977, but I'm not sure if it had implemented the three-key sequence yet or if it had borrowed that idea from the alt-ctrl-delete that was noted here.

Apple ][ Plus shipped with a hard "RESET" button not requiring any additional keys in combination. It had to be pushed pretty hard to make it depress, though. Unfortunately, it was somewhat close to "ESC" and occationally did get hit inadvertantly.

Then on the Apple ][e they fixed this problem by making the key-sequence be open-apple/reset in combination. You could catch this interrupt in software though, and ignore it. From a basic program, you could cause this interrupt to kill the program, reboot, or be ignored. It was just a few POKEs.

It doesn't matter what it is...

[Kynde]

...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.

fysically impaired?

[valentyn]

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? ;-)

Re:Windows' use of CTRL-ALT-DEL

[Telcontar]

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.

Re:Patent madness?

[nullard]

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.

Re:Er, that's a bit much....

[Mephie]

Honestly, though, he is modest. The IBM Campus in Raleigh had a career builder seminar once that he attended. He actually showed a video where he was speaking at a small conference where Bill Gates was in attendence.

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.

Re:Patent madness?

[Josuah]

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.

That's how alot of fiction

[prisoner]

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.