🚀 go-pugleaf

From: uunet!samsung!swlvx2!anomaly.sbs.com!idsvax!mikebw mikebw@idsvax.ids.com <uunet!samsung!swlvx2!idsvax.ids.com!mikebw@U
Date: Wed, 19 Jun 91 02:33:54 EST
Subject: RE: DOS 5.0 on 286

When installing MS-DOS 5.0 on a '286 machine, not everyone will have the
same pleasant experience as Doug.  Some '286 machines use the "NEAT"
chipset (for "new enhanced AT"), which will allow results similar to
Doug's.  Other will need an upper memory block manager from a third-
party vendor, such as QRAM from Quarterdeck.  In particular, the old
Award BIOS (c. 1985) that some less than honest Asian manufacturers
commonly install, even though it has known problems handling extended
memory, will fail some applications.  (Notably, MS Windows 3.0 will
crash in standard mode; this is a dead giveaway.)  But not all '286
machines are created equal, and MS-DOS 5.0 will rub it in.
 
On a related note, I have been playing with MS-DOS 5.0 fairly extensively
on my '386.  I recompiled PA0GRI NOS with the modification to main.c that
I suggested (blindly) and which Doug recently circulated, and it seems to
work fine.  Borland C++, however, fails when the protected mode compiler
is run, with a general protection fault if EMM386 is loaded in full EMS
mode, and with an "unrecognized expanded memory manager" error if EMM386
is loaded with the NOEMS switch.  The real mode compiler works fine.
Another wonderful undocumented MS-DOS 5.0 feature is that the EMM386
driver will rename itself if loaded with the NOEMS switch; instead of the
required EMS driver name EMMXXXX0, it will advertise the name $MMXXX0.
This seems fairly dangerous, and I suspect that the NOEMS switch may not
be a very good idea.

The real benefits of upgrading to MS-DOS 5.0 are not realized unless the
upper memory blocks are made available; I was able to get SMARTDRV, SHARE,
ANSI, and my printer spooler into upper memory instead of conventional,
giving a largest executable program size of about 625K.  Even NOS fits in
this.  I may try running QEMM again instead of the MS-DOS drivers, since
DOS should still be able to load itself high and this might handle the
Borland compiler a lot better.  If anyone has already gone down this road,
please drop me a note.

-- Mike Bilow, N1BEE @ KA1RCI.RI.USA.NA  (AX.25)
               mikebw@idsvax.ids.com  (Internet)
 


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