Question about how DOSEMU works

[complaw@hal-pc.org]

Hi:

I've downloaded the source code for DOSEMU, but was wondering if someone could
help me to look for the code for a specific feature.

I know that DOSEMU does some form of binary translation on instructions from the
DOS application.  However, for performance gains, it is usually faster to simply
allow direct (native) execution of the DOS application's instruction.  (See,
e.g., http://www.deatech.com/deatech/articles/linux_pc_vc.html ).  Does DOSEMU
allow (enable) direct execution of instructions?  I presume that all
instructions coming out of the DOS application are trapped.  Is that correct? 
Does that trap first look at the instruction and, depending on what it is,
simply allow the instruction to be executed (and, if not, do a binary
translation)?   If so, where in the source code is that decision logic?

Best wishes,

Ron