Article: Q124936
Product(s): Microsoft Windows NT
Version(s):
Operating System(s):
Keyword(s):
Last Modified: 08-AUG-2001
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The information in this article applies to:
- Microsoft Windows NT Workstation version 3.5
- Microsoft Windows NT Server version 3.5
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SYMPTOMS
========
MS-DOS-based applications that use serial communications may receive a serial
overrun error when running in a Windows NT version 3.5 virtual DOS machine
(VDM), even though the application ran correctly under MS-DOS. In a Basic
application, this would be seen as Error 57.
This has generally been seen after several hours of heavy communications at 9600
bits per second (bps).
CAUSE
=====
Because MS-DOS-based applications running under Windows NT are subject to CPU
time-slicing; they may not execute for extended periods of time (in Windows NT,
the highest priority task that is able to run always runs). To prevent lost
characters from serial communications ports, Windows NT virtualizes the port and
presents the characters to the MS-DOS-based application as that application
receives CPU time. The virtualization includes code to detect that an
application is ignoring the serial port; a problem in this code sometimes
incorrectly reports a serial overrun error.
STATUS
======
Microsoft has confirmed this to be a problem in Windows NT version 3.5. This
problem was corrected in the latest U.S. Service Pack for Windows NT version
3.5. For information on obtaining the Service Pack, query on the following word
in the Microsoft Knowledge Base (without the spaces):
S E R V P A C K
Additional query words: prodnt
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Keywords :
Technology : kbWinNTsearch kbWinNTWsearch kbWinNT350search kbWinNTW350 kbWinNTW350search kbWinNTSsearch kbWinNTS350 kbWinNTS350search
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