Path: utzoo!utgpu!news-server.csri.toronto.edu!rutgers!usc!zaphod.mps.ohio-state.edu!uakari.primate.wisc.edu!aplcen!haven!mimsy!nmrdc1!rdc30med
From: rdc30med@nmrdc1.nmrdc.nnmc.navy.mil (LCDR Michael E. Dobson)
Newsgroups: comp.windows.ms
Subject: Re: 386 enhanced mode
Message-ID: <1990Nov10.164023.8570@nmrdc1.nmrdc.nnmc.navy.mil>
Date: 10 Nov 90 16:40:23 GMT
References: <1990Nov7.204622.11812@cunixf.cc.columbia.edu> <125794@linus.mitre.org>
Distribution: comp.windows.ms
Organization: Naval Medical Research & Development Command
Lines: 53

In article <125794@linus.mitre.org> jcmorris@mwunix.mitre.org (Joe Morris) writes:
>In a recent article jpl5@cunixb.cc.columbia.edu (Jay P Lessler) writes:
>>In article <jcmorris.658004352@mwunix.mitre.org> jcmorris@mwunix.mitre.org (Joe Morris) writes:
>
>>>In article <7017@hub.ucsb.edu> 6600bori@ucsbuxa.ucsb.edu (Boris Burtin) writes:
>
>>>>I'm running Windows 3.0 on my 25mhz 386 with 2 megs, and I had some 
>>>>questions about this so-called enhanced mode.  When I type just "win"
>>>>at the command prompt, Windows throws me into STANDARD mode with 907k
>>>>RAM.  The manual says that with my configuration, it should default to
>>>>enhanced....
>>>>Is it normal for Windows not to default to enhanced mode? 
>
>>>Last time I looked the spec it said Win3 defaults to enhanced mode only 
>>>if you have a '386 (obviously) *and* you have 2M of memory *available to
>>>DOS*.  If DOS can't see at least 2M you get standard mode.
>
>>Are you sure about that?  I am running Windows on a '386 with **1.6M** of
>>memory.  Windows seems to be using disk space as extra (slow) ram, because
>>it boots up in '386 mode and shows about 4.5M free ram.
>
>Strange.  The Windows manual, p. 428, is slightly inconsistent.  Hear the Word:
>
>  Windows uses the following criteria when deciding what mode to use:
>
>  * Windows runs in 386 enhanced mode if your system is an 80386 computer
>    (or higher) with at least 2MB of memory (640K of conventional memory
>    and 1024K of extended memory).
>
>  * Windows runs in standard mode if your system is an 80286 computer (or
>    higher) with at least 1MB of memory (640K of conventional memory and
>    256K of extended memory).
>
>  * Windows runs in real mode if [none of the above].
>
>Note the conflict in the first bullet between "2MB" and "640K conventional
>memory plus 1024K extended memory".  One of my machines is a NEC PowerMate 386
>with 640+1024K; it defaults to standard mode, although I can force it to
>386 mode with the /3 switch.
>
>Joe Morris

This could be the source of confusion.  Does the NEC only have 640K+1024K?  My
386/20 clone actually has 640K convnetional + 384K High mem (640-1024K) +
1024K extended for a total of 2 Meg installed.  I can use sections of the 384K
at the end of the DOS workspace for shadow ram of video and system BIOS ROM.
If the NEC doesn't have this extra 384K RAM and you have enabled BIOS shadowing,
windows may actually see less than what it wants for enhanced mode.
-- 
Mike Dobson, Sys Admin for      | Internet: rdc30med@nmrdc1.nmrdc.nnmc.navy.mil
nmrdc1.nmrdc.nnmc.navy.mil      | UUCP:   ...uunet!mimsy!nmrdc1!rdc30med
AT&T 3B2/600G Sys V R 3.2.2     | BITNET:   dobson@usuhsb or nrd0mxd@vmnmdsc
WIN/TCP for 3B2                 | MCI-Mail: 377-2719 or 0003772719@mcimail.com