Date: Sun, 23 Apr 1995 13:12:45 +0300
From: eliz AT is DOT elta DOT co DOT il. (Eli Zaretskii)
To: andy AT smart DOT csie DOT ntu DOT edu DOT tw
Subject: Re: To use DMPI or not to use DMPI?
Cc: djgpp AT sun DOT soe DOT clarkson DOT edu

>	I use GRX with DJGPP.  But GRX cannot work under DMPI,
>	so that I add "nodpmi" within the variable "GO32".
>	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?

They are functionally the same, as far as DJGPP is considered.  You
shouldn't see any difference in functionality, unless you want to use
DPMI-specific services which go32 doesn't support.

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

Actually, DJGPP in its current version is *less* efficient in DPMI
mode, by about 10-15%.

>	Why cannot GRX work under DPMI?

Because it uses the fact that the video memory is mapped to a fixed
logical address, which can't be done under DPMI.  DJGPP v2.0 (due to
be released in a few months) will be a DPMI-only environment, so GRX
which goes with it will *have* to work under DPMI.