> -----Original Message-----
>
> Date:    Sun, 1 Jan 2006 16:31:38 -0800
> From:    David Gillett <[log in to unmask]>
> Subject: Re: Why is it a BLUE screen of death?

>   I believe the BSOD code uses the legacy BIOS CGA text output
> routines and
> so does not rely on the video card driver or the Windows screen-management
> code.
>   Many kernel functions are invoked by a signal from the processor that an
> instruction cannot immediately be executed.  For instance, a
> "page fault" is
> signalled by the CPU when a reference is made to a virtual address that
> doesn't currently map to an address in physical RAM.  Normally
> this invokes
> a kernel routine that will select an unused area of physical RAM (or de-
> allocate one in use if necessary) and read in the needed segment
> of the swap
> file, update the logical-to-physical translation table, and then tell the
> CPU to retry the memory access which should now work.
>   Very often, a BSOD will result when the CPU calls for this kind
> of kernel
> assistance from within one of these kernel routines, or when an invoked
> kernel routine cannot perform its task.  For instance the "page
> fault not in
> paged region" BSOD results when the required logical address isn't in the
> swap file, either.
>
> David Gillett
>
>
>
> On 1 Jan 2006 at 14:56, Dean Kukral wrote:
>
> > I was reading Peter's question about a possible failing video card,
> > and it got me wondering:  Why is it a **blue** screen of death when
> > your computer crashes?
> >
> > I have had black screens - that makes sense.  (SP2 caused them.)
> >
> > But why Blue?  It seems that if the computer crashes, then garbage
> > should be going to the video card and GIGO!
> >
> > Do video cards put out a blue screen by default when the input
> > directions make no sense?  Then, a blue screen would seem to make the
> > video card less of a likely culprit when there is a system crash, as
> > it is doing what it is supposed to be doing.
> >
> > Dean Kukral
-------------------------------------------

Hardware related technical reasons aside, I found the BSOD discussion lively
but it failed to explain WHY? I remembered a small filler article in an
issue of PCWorld (May 2004) that states,
        "Microsoft claims that the famous color scheme of the Windows crash
screen--aka the Blue Screen of Death--was picked for simple readability.
It's not like there were a lot of choices. Earlier versions of Windows
dropped down to a 16-color mode after a catastrophic event. In that palette,
the first background color (after black) is dark blue, as represented by the
HEX code 0x01. So maybe we can blame lazy programmers for the decision to
use blue. Though let's face it--the Cyan Screen of Death lacks menace."

Just a little tongue-in-cheek perspective. ;^)

Chris Ryan
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