Re: pentium bug continued [slightly offtopic]

Adam Wiggins (madman@zip.com.au)
Mon, 10 Nov 1997 11:31:01 +1100 (EST)


On Sun, 9 Nov 1997, Alistair Riddell wrote:

> I think such things as the keyboard LEDs and Ctrl+Alt+Del are handled by
> the BIOS/keyboard controller hardware unless the OS takes control of them.
>
Its not a bois/OS thing, the cpu is shut down so it cant execute
OS or bios code. What might be happening here is that the cpu never got
put into protected mode like it does in win95 and linux and just remainned
in 8086 mode as all intel cpu's do when they first boot. It might get
effected differently in this mode?
Cheers Adam

> Remember, keyboard LEDs and Ctrl+Alt+Del work almost as soon as the
> machine is switched on, long before the OS is loaded.
>
> On Sun, 9 Nov 1997, Stephan Meyer wrote:
>
> > I have something very strange to report.
> >
> > I successfully crashed my box under linux with f00fc7c8.
> > I successfully crashed my box under win95 with f00fc7c8.
> > Both hard-froze, no mouse movement, no keyboard LEDs... etc.
> >
> > The machine did not hard-freeze under DOS!!!! Though the debug program
> > locked, I was able to (a) toggle the keyboard LEDs with my keyboard and
> > (b) reboot the machine by pressing ctrl-alt-del.
> >
> > This is very strange when compared to the opinions that have been
> > surfacing on this list lately.
> >
> > I used the same method for crashing both DOS and windows. I started debug,
> > assembled the byte sequence and pressed "g".
> >
> > contents of /proc/cpuinfo:
> > --------
> > processor : 0
> > cpu : 586
> > model : Pentium 75+
> > clock_speed : 120 MHz
> > vendor_id : GenuineIntel
> > stepping : 11
> > fdiv_bug : no
> > hlt_bug : no
> > fpu : yes
> > fpu_exception : yes
> > cpuid : yes
> > wp : yes
> > flags : fpu vme de pse tsc msr mce cx8
> > bogomips : 48.03
> > --------
> >
> > This is an Olivetti P120S notebook with a mobile pentium in a socket.
> >
> > Regards,
> > - Stephan
> >
> > ------------------------------------------------
> > Stephan.Meyer@pobox.com
> > meyerst@informatik.uni-muenchen.de
> > http://pobox.com/~stephan.meyer/
> > 2A 64 F0 73 02 91 10 FC 18 CC 83 1E E2 2C 7E 79
> >
> > So what would an angel say
> > The devil wants to know
> >
> >
>
> --
> Alistair Riddell - BOFH
> IT Support Department, George Watson's College, Edinburgh
> Tel: +44 131 447 7931 Ext 176 Fax: +44 131 452 8594
>