Bork!Bork!Bork! Even after a year of readers sending in photos taken of error screens they’ve seen out and about for The Reg‘s Bork column, the infamous Windows “Blue Screen of Death” has remained a mainstay. However, have you wondered why blue is the colour?
Retired Microsoft engineer Dave Plummer took to his YouTube channel over the weekend to give us his view on matters.
Firstly, “I never once heard the term ‘blue screen of death’ at Microsoft,” he recalled, “We called it primarily just a blue-screen or, more frequently, a bug-check.”
We’ll stick with BSOD, thanks Dave.
Plummer then highlighted the infamous onstage BSOD back in 1998 at the Comdex trade show in Vegas, when an impossibly youthful Chris Capossela, now MS’s executive vice president of Consumer Business, was showing off Windows 98 to Bill Gates. Attaching a USB scanner resulted in a visit from Dr Blue.
The former engineer also mentioned a later incident involving a demo of the driving game Forza. Everything held up in rehearsals until the actual demo, where Windows did its thing once again. That one was down to the programmer’s arch-nemesis: the memory leak.
The blue screen we all know and love today usually occurs when something has happened to cause the Windows kernel to call the KeBugCheck function and bring down the system in what Microsoft brands a “controlled” fashion. The function should only be called when an unrecoverable error has occurred that threatens to corrupt the system itself.
“Calling that API,” remarked Plummer, “is a little like pulling the fire alarm in a theatre.”
A BSOD might mean work in progress was lost, he added but “it’s better than corrupting already saved work in the form of data loss.”
It was not always thus. In the early days it was sometimes possible to carry on in the hope of saving that almost-finished opus before the operating system threw in the towel once and for all.
“With NT,” said Plummer, “it’s not so simple. It’s supposed to be robust and secure and trustworthy, meaning ‘borked’ was not really in our vocabulary.”
While today’s BSODs are generally the result of something like an iffy driver, and tweaks to the user mode driver model have improved things, screens of blue have been a fixture of Windows since v1.0.
The early blue screens merely threw up garbage that was generally unreadable. It was an indicator that a Bad Thing had happened, yet it wasn’t until the advent of Windows 3.1 in April 1992 that things got a little more informative and helpful with what Plummer called “the control-alt-delete” screen.
It was not quite a BSOD (indeed, Windows 3.1x could crash back to MS-DOS when the wheels properly came off) and being triggered by hitting ctrl+alt+delete when a program stopped responding, the screen (or dialog) was both blue and an indicator that all was not well.
Raymond Chen laid claim to the blue control-alt-delete screen (or dialog) of Windows 3.1 itself, however it was Steve Ballmer that infamously came up with the text to give the user the opportunity to try and kill the non-responsive app.
Windows NT was considerably better at dealing with errant processes, but why blue for its bugcheck? A tribute to the precedent set by Windows of old? Perhaps just a quick way of knowing which machine in the test lab had fallen over?
Plummer tracked down the developer behind Windows NT’s blue screen (who he identified as John Vert having trawled through the code.) The blue? Nothing to do with labs, or earlier incarnations of Windows. As Plummer pointed out, “Windows was not the original UI for NT, the OS/2 Presentation Manager would have been.”
The choice came down to the lowest common denominator for the video hardware on which NT ran. There were only a limited number of colour text mode available, with white on a dark colour seeming a good choice.
And the blue? “Put simply, because John’s dev machine was a MIPS RISC box, and the firmware on that machine was white on blue.
“And in fact, his favourite editor at the time was SlickEdit, and the default text colours for SlickEdit were also white on blue.
“You could boot, code, and crash all in the same colour scheme: white on blue.”
Blue screens have continued into Windows 10, even if things have been updated slightly and the shade of blue is not quite what it was. Other colours have crept into the mix, including the green versions faced by Windows Insiders. It is also possible to alarm onlookers with a custom tint.
We’ve seen our fair share of BSODs and attempted to revive Windows 3.1 with Chen’s ctl+alt+delete dialog on many occasions in our time, and we also have a certain fondness for the red text of an Amiga Guru Meditation error. That, however, is a story for another day. ®