Robert King wrote in a message to Jeff Glatt:

 RK> 32bit device drivers DO exist for OS/2. MANY of them. 

There is some confusion here.  Some types of device drivers, such as
physical device drivers, are inherently 16-bit and use 16-bit interfaces to
the kernel. Other types of device drivers, such as virtual device drivers,
are inherently 32-bit and use 32-bit interfaces to the kernel.

Any device driver can be compiled (or written in assembly language) to
exploit the 32-bit registers and 386 instruction set, as long as it
preserves the registers it uses and follows the correct interface and
calling conventions.

In my opinion, the module that probably takes the worst performance hit for
being 16-bit instead of 32-bit is HPFS.IFS.  Some drivers, such as COM.SYS,
probably operate no worse as 16-bit drivers than they would as 32-bit
drivers, especially when managing 8-bit devices.  On the other hand, the
file system is the most critical component of OS/2 in terms of performance,
and a 32-bit file system driver would probably be a big improvement.
 
-- Mike


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