Windows 95/98/ME boot into real mode, load a slightly modified version of DOS, then load the Win32 environment on top. Win9x is still (potentially) reliant on realmode 16bit drivers.
Windows NT (2000 and XP are included) was a ground up rewrite (Started as a combined effort, IBM and Microsoft together, eventually creating OS/2 And Windows NT) and does not use DOS or anything similar. It loads into protected mode as soon as possible, before loading any drivers or anything more then is needed to read from the hard drive and display errors to the video card. Once in protected mode, it discards all elements of the realmode boot and switches over to it's own drivers. Unfortunately, (For a true multiuser environment) the WinNT kernel is integrated with the GUI. It's designed around having a GUI present, and doesn't behave nicely without one. All versions of NT (4.0 and up, anyway -- I've basically forgotten about 3.51 and earlier) have the ability to run multiple users which maintain unique memory spaces and basically cannot interfere with each other They can see all processes of course, but cannot interact with them (Assuming proper ACLs are in place). The problem is, these users only have one GUI to interact with, and there is no easy way to redirect/capture calls to the GUI and determine which video driver should receive the messages. Citrix and terminal server are an attempt around this, but you still run into challenges with programmers that did not follow best practices, and store configuration and/or state information on the hard drive in the application directory, or some other location central to the system, rather then a session specific location. I have to admit, I've done this on a few occasions, but only on applications where I needed to ensure that only one instance ran at a time on a given machine (Servers, weblog->database import runs, etc), and I took appropriate precautions to ensure that a second instance would refuse to run. I still count myself as a lazy programmer though, since I didn't do things "properly" ----- Original Message ----- From: "Christopher Koeber" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Saturday, December 15, 2001 6:11 PM Subject: Re: VNC is Powerful, could it become like Citrix > Isn't Windows like that as well, since Windows is basically on top of MS-DOS > .. With Windows XP Microsoft is trying to get away from that, but I still > believe that MS-DOS is the core of all Windows systems. What does everyone > else think??? > > Sincerely, > > Christopher > ----- Original Message ----- > From: "David Smith" <[EMAIL PROTECTED]> > To: <[EMAIL PROTECTED]> > Sent: Saturday, December 15, 2001 4:13 PM > Subject: Re: VNC is Powerful, could it become like Citrix > > > > >On Fri, 2001-12-14 at 13:17, Christopher Koeber wrote: > > >> VNC s excellent, well, at least in my opinion. What I am wondering is > if VNC > > >> could become like Citrix, allowing multiple users to connect to a > single > > >> windows machine. This would make VNC great, wouldn't it? Anyone's > opinion is > > >> greatly valuable! > > > > > >Hmmm... UNIX has only had this capability out of the box for, oh, 20 > > >years or so... LOL > > > > UNIX's graphic display is separate from it's core OS (you can run > > UNIX without a graphics card and monitor), and for that matter the > > graphics subsystem (X) has two parts, the X server itself, which > > provides base functions, and the window manager that defines how > > things look and act. These can run on separate machines (how PC X > > servers work, by running the window manager locally you get more > > speed, and can do neat things like integrate it into the main > > graphics environment). > > > > On the down side, this separation leads to more overhead and a slower > > graphics environment, and makes if very hard to integrate things like > > hardware acceleration into the process. > > -- > > -------------- > > David A. Smith > > <[EMAIL PROTECTED]> > > The box said: "Needs Windows 98 or better," so I bought a Macintosh. > > --------------------------------------------------------------------- > > To unsubscribe, mail [EMAIL PROTECTED] with the line: > > 'unsubscribe vnc-list' in the message BODY > > See also: http://www.uk.research.att.com/vnc/intouch.html > > --------------------------------------------------------------------- > --------------------------------------------------------------------- > To unsubscribe, mail [EMAIL PROTECTED] with the line: > 'unsubscribe vnc-list' in the message BODY > See also: http://www.uk.research.att.com/vnc/intouch.html > --------------------------------------------------------------------- > -- The nice thing about standards, there is enough for everyone to have their own. --------------------------------------------------------------------- To unsubscribe, mail [EMAIL PROTECTED] with the line: 'unsubscribe vnc-list' in the message BODY See also: http://www.uk.research.att.com/vnc/intouch.html ---------------------------------------------------------------------
