Vistacom Problems When Switching COM Ports (82407)
The information in this article applies to:
- Microsoft Windows 3.0
- Microsoft Windows 3.0a
- Microsoft Windows 3.1
- Microsoft Windows 3.11
This article was previously published under Q82407 SUMMARY
Under Microsoft Windows, Vistacom and its associated terminate-and-stay-
resident (TSR) program, DEVLOAD.EXE, can cause interrupt request line (IRQ)
conflicts when running in 386 enhanced mode.
Disabling the Combuff device in the Windows SYSTEM.INI file corrects this
problem.
MORE INFORMATION
Vistacom is a terminal emulator manufactured by Control Data. Vistacom
can cause interrupt conflicts when you disconnect from a COM port and
then try to use another COM port on the same IRQ while running in a
Windows virtual machine. For example, disconnect from COM3 and then
try to use COM1. Under the standard IBM serial port configuration,
COM1 and COM3 use the same interrupt (IRQ 4).
To correct this problem, disable the Combuff device in the Windows
SYSTEM.INI file. In the [386enh] section of the SYSTEM.INI, either set
the line "COMxBuffer=0" (where "x" is the COM port number) or remove
the line "device=*combuff".
Vistacom is manufactured by a vendor independent of Microsoft; we make
no warranty, implied or otherwise, regarding this product's
performance or reliability.
| Modification Type: | Minor | Last Reviewed: | 7/7/2005 |
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| Keywords: | KB82407 |
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