Subj : Interrupts
To   : Jonathan De Boyne Pollar
From : Lee Aroner
Date : Tue May 29 2001 02:45 am

 LA> I had simply assumed that OS/2 used the same invalid int trick to 
 LA> switch rings as Win does.

JdBP> The interrupt(s) used on DOS-Windows and and Windows NT 
    > aren't "invalid".  They are perfectly valid.  Their entries 
    > in the IDT point directly to the syscall dispatch routines.

   <sigh> OK, poor choice of language. The int is fine.

   What is done to switch control from the application to the OS is 
   a jump into the bios copyright notice to force a processor 
   exception.

   Happy now?


                                       LRA


 -- SPEED 2.01 #2720: Sign Here: _______________________________

--- Maximus/2 3.01
 * Origin: Top Hat 2 BBS (1:343/41)

.