From: Charles Sandmann <sandmann AT praline DOT no DOT NeoSoft DOT com>
Subject: Re: To use DMPI or not to use DMPI?
To: andy AT smart DOT csie DOT ntu DOT edu DOT tw (Oz the Wizard)
Date: Sun, 23 Apr 1995 11:25:41 -0500 (CDT)
Cc: djgpp AT sun DOT soe DOT clarkson DOT edu

> 	I don't know what the effects are caused by "nodpmi" to GCC?  I found
>   that if I force GCC not to use DPMI, then GCC will use VCPI instead. 
> 	Which is better? DMPI or VCPI?

Neither is better, they are different memory control interfaces with different 
purposes.  The problem is that VCPI is not provided under many environments
like Windows and OS/2, so the *ONLY* way to run in those environments is
DPMI.  DPMI provides more features but less control over your environment,
so some DJGPP features provided under VCPI cannot be provided under DPMI.

> 	Will the efficiency of go32 be degraded if I don't use DMPI?

GO32 runs slower under DPMI.  V2 runs faster under DPMI than V1.x does under
VCPI.  Supporting multiple memory interfaces is a nightmare, and that is
one of the reasons V2 is designed to use DPMI.

> 	Why cannot GRX work under DPMI?

GRX 1.x uses GO32 features to access different graphics memory banks.
This graphics driver function cannot be performed under DPMI - so the
graphics drivers and GRX need to be re-written to work under DPMI.
Csaba has completed this task for the most part - GRX 2.0 works under
DPMI and is almost finished.