Subj : Interrupts
To : Vitus Jensen
From : Lee Aroner
Date : Wed May 23 2001 09:37 am
RV>> First, OS/2 doesn't use interrupts. You have to use API calls.
RV>> Second, since OS/2 is a multitasking OS, it manages memory much
RV>> differently than DOS does.
LA> Not to niggle the point, but of course OS/2 uses interrupts. Each
LA> and every one of those API calls is a wrapper around an interrupt
LA> call.
VJ> Well, to be exact: OS/2 uses callgates to jump into kernel code. Callbacks
> are similar to interrupt gates in that they switch
> priviledge levels and have a predefined entry point into
> the kernel but they additionally copy bytes from lower to
> higher level stacks while swichting (byte count defined in
> the callgate). Something what a interrupt gate won't do.
> It is a common design of OSses to do this switching via a
> software interrupt but OS/2 is different.
Ah, but are not those callgates accessed through an interrupt?
It's irrelevant that it is an invalid interrupt, a spade 's a
spade after all...
LRA
-- SPEED 2.01 #2720: "Too much of a good thing is wonderful." <Mae West>
--- Maximus/2 3.01
* Origin: Top Hat 2 BBS (1:343/41)
