Running After Dark: Unable to Access Serial and Parallel Ports

ID: Q128796

The information in this article applies to:

Microsoft Windows NT operating system version 3.1
Microsoft Windows NT Advanced Server version 3.1
Microsoft Windows NT Workstation version 3.5
Microsoft Windows NT Server version 3.5

SYMPTOMS

When After Dark version 2.0 loads in Windows NT and you attempt to start an application that uses a device connected to a serial communication (COM) port, the following error message appears:

The selected COM port is either not supported or is being used by another device.

Select another port.

If you select another port, the same error message appears again.

CAUSE

This problem occurs when After Dark 2.0 SystemIQ Activity Monitor runs before you start the application using the COM ports.

SystemIQ Activity Monitor monitors serial and parallel port activity as well as CPU load. As activity of the CPU or external devices increases, After Dark does not blank out the screen to provide maximum processing time to other tasks.

WORKAROUND

To work around this problem:

Run the After Dark Control program and choose Setup.

Clear the SystemIQ Activity Monitor check box.

Using a text editor, open the AD_PREFS.INI file. This file is located at the Windows NT %SystemRoot% directory.

In the [After Dark] section of AD_PREFS.INI, change "WatchComPorts=1,2,3,4" to ";WatchComPorts=1,2,3,4" (without the quotation marks).

NOTE: If one specific COM port is used by the COM device continuously, such as Terminal or Remote Access Service), remove only the port number. You do not have to remark out (;) the entire line.

If you experience problems with the parallel ports, change the "WatchParallelPorts=1,2,3" entry in the [After Dark] section of AD_PREFS.INI file to ";WatchParallelPorts=1,2,3" (without the quotation marks).

NOTE: If one specific parallel port is used by a parallel device continuously, remove only the port number. You do not have to remark out (;) the entire line. The problem with parallel ports does not cause the message above to appear.

The product discussed here is manufactured by Berkeley Systems, Inc., a vendor independent of Microsoft; we make no warranty, implied or otherwise, regarding these products' performance or reliability.

Additional query words: 3.10 ad prodnt

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