Some senseless babbling from Ivan Todoroski to Mario Semo
on 29 Nov 98  08:56:00 about Guess who's back... ;)...

[snip]
 IT> And here is a great way to TOTALLY and IRREVOCABLY freeze your
 IT> OS/2 system. Mouse will stop, and not even Ctrl-Alt-Del or
 IT> Ctrl-Alt-NumLck-NumLck will work!

 IT> Take any DOS assembler (even DEBUG will do) and create a simple
 IT> program (.COM or .EXE, no matter) with this piece of code in it:

 IT> cli
 IT> x:
 IT> jmp x

 IT> Execute this in a DOS window.

 IT> Hope you closed all the applications first... ;)

That will only work on early-step 486's from Intel, and non-Intel 
processors.

All late-step 486 and higher processors for Intel have instructions to 
allow fast interrupt virtualization, which OS/2 takes advantage of.  The 
DOS window can be closed easily.

Of course, this has absolutely nothing at all to do with priority.  The 
"cli" instruction clears the interrupt flag (i.e. disables
interrupts), and 
the rest is just a loop.

Any system with a watchdog timer (with any CPU) will also not be locked up.

Mike Ruskai
thanny{at}home.com


... Back off man...I'm a scientist.
--- Renegade v05-11 Exp