Re: TI-H: Off Topic, Windows 95 trivia
[Prev][Next][Index][Thread]
Re: TI-H: Off Topic, Windows 95 trivia
Now time for the timeline. Its kinda funny, since everything is
impliminted by Apple, then used by microsoft. They still havn't copied the
'find'.
But I won't include it because it includes some ASCII characters that might
hurt any Pent computers with the old math bug. :)
>As list traffic has been pretty low lately, and given the
>propensity of this list to discussion of operating systems,
>I thought this tidbit might intrest some of you.
>
>Many of you probably know about the layer of windows that
>involves Kernel32, GDI32, User32, and etc, but most people
>are unaware of the lower layer, consisting of (among other
>things), VMM (the real heart of windows), IFSMgr, V86MGR,
>VSDLDR, and etc.
>
>VMM, the windows Virtual Machine Manager, in its basic
>32 bit format has been around for (suprise!) nearly 9
>years now. On May 22, 1990 Microsoft released Windows
>3.0 Enhanced mode, which, contrary to popular opinion,
>is a true operating system, not just a program that runs
>"on top of" DOS. Its actually possable that windows
>as a true OS could have had its roots set way back in
>1988 with Windows/386 2.0. We've had a true 32 bit
>protected mode operating system on our computers for
>8 years now!
>
>Windows runs the old 16 bit DOS code in virtual 86 mode,
>which means that by using the Hook_V86_Int_Chain call
>provided by VMM, system VxDs can capture and emulate
>any interrupt call, even if they originate in the old
>DOS code. Windows emulates most of the file access
>calls (hence 32 bit file access in WfW 3.11), and many
>others.
>
>Remember WfW 3.11 with 32 bit file access? Guess what?
>That 32BFA layer is a pre-beta of what now exists in
>Win9x. Microsoft ads for WfW 3.11 (late 1993) bragged
>about how 32BFA was based on "the 32-bit file system
>for our Chicago project" WfW 3.11 includes 32-bit
>file system VxDs such as IFSMgr, VCACHE, and VFAT,
>just as win95 does. Its intresting that the 32BFA
>could be lifted directly out of the 95 project and
>dropped into 3.11 without any major changes to the 3.11
>VMM. Everything necessary to support 32BFA has been in
>windows since v3.0!).
>
>Essentially, windows uses DOS like a big and complex
>device driver, allowing it to handle many of the
>system interrupt calls in the 16 bit code. There are
>a couple of reasons MS did this. One is that the DOS
>code has been well tested and is known good, if it were
>to be rewritten it would have to be extensivly retested,
>which is time consuming and expensive. Also, if all
>that code were 32 bit, the memory requirments would
>have increased by nearly 40%! (32 bit code is by
>nature fatter than 16 bit code).
>
>So, my whole point is that since windows 3.0 could
>run in enhanced mode (and possably sooner), it has
>not been a program that runs on dos, it is a powerful
>and integrated part of the OS, extending and using
>MS-DOS. Microsoft kept much of this secret, much
>of this architecture is not clearly documented, and
>indeed, Microsoft has released statements that are
>clearly misleading. In WfW 3.11, all of the new
>32BFA code was completely undocumented, only Microsoft
>would use it. Only a handful of people know the
>real details behind windows, they are the people
>who study windows architeture and understand the
>details of writing device drivers.
>
>Never would have guessed huh?
>DK
>
>______________________________________________________
>Get Your Private, Free Email at http://www.hotmail.com
Follow-Ups:
References: