Mac’s Blue Screen of

Have you ever heard of BSOD? What about the Blue Screen of Death? That’s that blue screen with white text that appears when Microsoft Windows crashes in a particularly nasty way. Basically it means something really bad happened, bad enough that Windows could not continue to operate.

Published: Sat 26 Nov 2011, 11:20 PM

Last updated: Tue 7 Apr 2015, 8:03 AM

If you search online for BSOD you will find plenty of examples of where Windows computers in funny or embarrassing situations have been struck by the blue screen. In fact, Microsoft chairman Bill Gates himself was struck by it during a demo of Windows 98 at the 1998 COMDEX show. Gates recovered quickly by joking: “That must be why we’re not shipping Windows 98 yet.”

When it comes to computers, the kernel is, according to Wikipedia: “the main component of most computer operating systems; it is a bridge between applications and the actual data processing done at the hardware level.” In other words, look at it as the very core of the operating system; if something goes wrong and it can’t continue to function, it panics.

Although it’s not blue, Mac OS X has its own screen of death and it’s called the kernel panic message. In previous versions of Apple’s operating systems you would have seen a sad Mac icon if the computer couldn’t start up or a bomb if something crashed while running.

In Mac OS X the message is no less final although a bit less iconic, pardon the pun.

Starting out in versions 10.0 and 10.1 the kernel panic wasn’t very pretty. Much like the Windows equivalent it just printed out a bunch of code on the screen, starting with something like “panic(cpu 0): Could’t register to modules.”

This improved with 10.2 and above, where you got a much friendlier window on the screen saying “You need to restart your computer,” followed by instructions, in four languages no less.

After Mac OS X 10.3 the kernel panic window kept its look other than it became dark with light text on it (see it at When you see this message all you can do is follow the instructions and force a shutdown of your Mac. You do this by holding down the power buttons for a few seconds until the Mac shuts down. Then you can start it up again and hopefully it will then work.

I heard someone say last week that they don’t like Mac people who says that their Mac never crashes. I agree. If you’ve been lucky enough to have used a Mac for a long period of time and it’s not crashed or you’ve not seen a kernel panic, you’re undoubtedly lucky. It’s happened to me many times, even a few times when I’ve done simple things like plug in a USB hard drive.

But even if a Mac is not immune to problems and has its own Blue Screen of Death, it’s no less fun to see panic-stricken Windows PCs in public places like airports and shopping malls.

Magnus Nystedt, @mnystedt

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