home *** CD-ROM | disk | FTP | other *** search
- Path: sparky!uunet!zaphod.mps.ohio-state.edu!cis.ohio-state.edu!rutgers!ub!acsu.buffalo.edu!ziniuwei
- From: ziniuwei@acsu.buffalo.edu (Ziniu Wei)
- Newsgroups: comp.unix.misc
- Subject: Re: X11 and Windows NT (was: Windows NT Report)
- Message-ID: <C0p7Gq.Mvw@acsu.buffalo.edu>
- Date: 11 Jan 93 16:36:26 GMT
- References: <1993Jan9.034843.28167@athena.mit.edu> <1992Dec23.160416.2512@nsisrv.gsfc.nasa.gov> <C0Do0q.pn@alsvid.une.edu.au> <1993Jan5.151421.24773@nsisrv.gsfc.nasa.gov> <1iocmlINN399@usenet.INS.CWRU.Edu>
- Sender: nntp@acsu.buffalo.edu
- Organization: State University of New York at Buffalo/Comp Sci
- Lines: 50
- Nntp-Posting-Host: pegasus.cs.buffalo.edu
-
- In article <1iocmlINN399@usenet.INS.CWRU.Edu> cq377@cleveland.Freenet.Edu (David C. Williss) writes:
- >
- >In a previous article, vlcek@mtl.mit.edu (Jim Vlcek) says:
- >
- >>williams@nssdcs.gsfc.nasa.gov (Jim Williams) writes:
- >>
- >>>Microsoft is the only player without X11 support. In my opinion, if
- >>>they shun X11, they will do so at their own peril.
- >>
- >Actually, Microsoft can't really stop it. We've written an X Server for
- >Microsoft Windows 3.1 and plan to do NT eventually. Of course,
- >everything it does has to go through MS Windows, which makes things
- >slower than they need to be, but it works. It just opens one big window
- >(Microsoft type) and makes that the "screen". The only real problem
- >is that Microsoft windows isn't really a multitasking operating system
- >in the same sense that Unix is. Unix is preemptive, where as in
- >Microsoft, a program has to give up control to let other proceses run.
-
- I think the problem is in DOS. Because DOS should run on a lot of kinds of
- hard disks, it should call the ROM BIOS when doing IO. The ROM BIOS is not
- reenterable, i.e. it can not perform the asynchronous disk IO. The
- asynchronous IO is crucial to multitasking because another process can take the
- CPU when one process is block in an IO. In multitasking of Windows, if one
- task is doing IO, all the rest should wait for it until the ROM BIOS IO
- returns. In Unix, the device driver is in the kernel, so the kernel bypasses
- the BIOS to perform the low level IO. When one IO is started, the kernel put
- the IO in a waiting queue and schedule another process. When the IO is done,
- the device will interrupt the kernel.
-
- This is a satiric paradox: Microsoft has to make DOS run on every kind of
- PC clone, hence it needs ROM BIOS to handle different kinds of hard disk. The
- ROM BIOS makes DOS compatable while makes real multitasking impossible, unless
- new reenterable BIOS is used.
-
-
-
- /|
- / |
- / | Ziniu Wei
- _____/___|_____ Center of Excellence of Document Analysis (CEDAR)
- / / / / Department of Computer Science
- / / / / State University of New York at Buffalo
- /____/____/____/
- | /
- | / Internet: ziniuwei@cs.buffalo.edu
- | /
- |/
-
- --
- Old programmers never die, they just branch to a new address.
-