Path: utzoo!utgpu!water!watmath!clyde!att!osu-cis!tut.cis.ohio-state.edu!mailrus!cornell!uw-beaver!microsoft!gordonl
From: gordonl@microsoft.UUCP (Gordon Letwin)
Newsgroups: comp.sys.ibm.pc
Subject: Re: DOS 4.0
Summary: DOS 4.0 explained
Message-ID: <1656@microsoft.UUCP>
Date: 29 Jul 88 16:15:01 GMT
References: <611@wa3wbu.UUCP> <6065@spool.cs.wisc.edu> <4530@ut-emx.UUCP> <3301@tekgen.BV.TEK.COM>
Organization: Microsoft, Inc., Redmond, Washington
Lines: 42


   In article <3301@tekgen.BV.TEK.COM>, stever@tekgen.BV.TEK.COM (Imants Golts) writes:
   > 
   > Whatever "Inside OS/2" says about DOS 4.0 is now seemingly outdated by IBM's
   > offering of PC-DOS 4.0.  It is my understanding that Microsoft has
   > offered MS-DOS 4.0 for quite a while to OEM's in Europe primarily
   > as a multitasking operating system.  This MS-DOS 4.0 is not the
   > PC-DOS 4.0 now being offered by IBM.   

True.  "DOS 4.0" was an internal name for what was sold as a special OEM
product.  I don't believe that those OEMs retailed it as "DOS 4" because that
would confuse their customers.  To the end user, DOS 4 looked like DOS 3, and
I'm sure was sold as that.

Since the name "DOS 4" never hit the streets on a product, IBM felt free
to use that for the next DOS upgrade.  Nothing like a little confusion
to make one's day.  My personal theory is that IBM did it because one
of their employees has a rival OS/2 book out that doesn't mention
DOS 4.0 ( :-) )

   > So the question is, will the new MS-DOS 4.0 have undocumented 
   > multi-tasking?  (I doubt it since multitasking is the intended
   > domain of OS/2 where it is designed into the OS  from the start,
   > and IBM and MS would certainly want some reason for the customer to
   > go to OS/2!)
   > 
   > And what is Microsoft going to call the old (multi-tasking) MS-DOS 4.0?

No, MS-DOS 4.0 and PC-DOS 4.0 have no multitasking.  They're derived
from the 3.x lineage.  The lack of multitasking isn't mainly a matter
of wanting people to go to OS/2 - multitasking is very limited in a
DOS environment because of the lack of memory, the lack of protection, and
the inability to move programs around in memory once they've started.  This
last also effectively precludes swapping.  OS/2 of course multitasks in
protect mode and doesn't multitask within real mode (although it does
multitask BETWEEN real and protect mode.  Lotsa late nights here)

As for the OEM product, I don't know what we call it when we discuss it
with OEMs, but I guess we'll figure something out.

	Gordon Letwin
	Microsoft