wine users - Nov 2008 - How does Wine simulates Windows presence?

Here is a rather technical (and maybe strange) question: how does Wine simulates
Windows presence at the low level?
I know that operating systems usually make themselves present using interrupts
(for i386 at least), for example interrupt 0x21 for DOS and 0x80 for Linux. I
suppose there is another interrupt used by Windows too. What I am wondering is
how Wine makes it available to the Windows executable loaded in memory. I have
read a big amount of source code from Wine (although not even 1% I'm sure),
but so far no clue about where this small initialization code is hidden. Could
someone point me to where it is, or even better, to a documentation?

Thanks in advance :-)

PS: In case you wonder why this would interest me, the reason is I just want to
mess with this mecanism for fun :-P

fafner wrote:
> Here is a rather technical (and maybe strange) question: how does Wine
simulates Windows presence?
By providing the same API.

What "low level" are you talking about? Kernel? Native API?

What ever you said about interrupts makes no sense to me. Wine does emulate DOS
interrupt calls. However windows apps don't use any interrupt calls.