DOCUMENT:Q103332  23-AUG-1993  [W_NT]
TITLE   :Mouse Races and Jumps Across Screen
PRODUCT :Windows NT
PROD/VER:3.10
OPER/SYS:WINDOWS
KEYWORDS:BUGLIST

----------------------------------------------------------------------
The information in this article applies to:
 
 - Microsoft Windows NT operating system, version 3.1
 - Microsoft Windows NT Advanced Server, version 3.1
----------------------------------------------------------------------
 
Bug #:15640
 
SYMPTOMS
========
 
Your mouse pointer races across the screen in sudden bursts. It is
difficult to control and often goes beyond what you aim for.
 
CAUSE
=====
 
You have a serial mouse connected to a port based on the 16550 UART
chip. The port adapter or motherboard uses hardware buffering rather
than software buffering; and, the buffer is turned on. The mouse races
because the hardware buffer is caching mouse movements and releasing
them to the mouse driver in blocks. The mouse driver interprets these
streams of movements as accelerated input and drives the mouse pointer
accordingly.
 
RESOLUTION
==========
 
Disable the hardware buffering for the serial port the mouse is
connected to, or choose a different port.
 
Additional reference words: 3.10 mouse-rodeo
KBCategory:
KBSubCategory: HRDWR

=============================================================================

THE INFORMATION PROVIDED IN THE MICROSOFT KNOWLEDGE BASE IS
PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND.  MICROSOFT DISCLAIMS
ALL WARRANTIES, EITHER EXPRESS OR IMPLIED, INCLUDING THE WARRANTIES
OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.  IN NO
EVENT SHALL MICROSOFT CORPORATION OR ITS SUPPLIERS BE LIABLE FOR
ANY DAMAGES WHATSOEVER INCLUDING DIRECT, INDIRECT, INCIDENTAL,
CONSEQUENTIAL, LOSS OF BUSINESS PROFITS OR SPECIAL DAMAGES, EVEN IF
MICROSOFT CORPORATION OR ITS SUPPLIERS HAVE BEEN ADVISED OF THE
POSSIBILITY OF SUCH DAMAGES.  SOME STATES DO NOT ALLOW THE EXCLUSION
OR LIMITATION OF LIABILITY FOR CONSEQUENTIAL OR INCIDENTAL DAMAGES
SO THE FOREGOING LIMITATION MAY NOT APPLY.

Copyright Microsoft Corporation 1993.