Date: Sun, 29 Dec 1996 21:02:05 -0500
Message-Id: <199612300202.VAA22138@delorie.com>
From: DJ Delorie <dj AT delorie DOT com>
To: grendel AT ananke DOT amu DOT edu DOT pl
CC: djgpp AT delorie DOT com
In-reply-to: <199612300146.CAA29496@math.amu.edu.pl>
	(grendel AT ananke DOT amu DOT edu DOT pl)
Subject: Re: DPMI incorporation...


> And what about the 0x0602 -- 0x0604 and 0x0702, 0x0703 functions? The 
> DPMI 0.9 specification says they have to be supported by a server to 
> be fully 0.9 compatible. If the functions are part of the 
> specification then any DPMI client CAN rely on them without thinking 
> whether they are available in this or that server - and that means 
> 286-compliant servers would have to implement them. But how? 286 
> hardware does not support pages.

From the spec:

   "This function is ignored by DPMI implementations that do not
    support virtual memory; the function will return the Carry flag
    clear to indicate success, but has no other effect."

   "This function will always succeed on hosts that do not implement
    demand-paged virtual memory."

Thus, you can implement a compliant DPMI server on a 286.

The functions that require virtual memory are 0x0504 through 0x050a,
and they are DPMI 1.0 functions.