PCMCIA Modem Fails When Set to Windows NT Default

The information in this article applies to:

• Microsoft Windows NT Workstation version 3.51
• Microsoft Windows NT Server version 3.51
• Microsoft Windows NT Workstation version 4.0
• Microsoft Windows NT Server version 4.0

SYMPTOMS

When you install or upgrade to Windows NT 3.51 or NT 4.0, some PCMCIA modems or fax-modems may not function properly with the Windows NT default base I/O port address and interrupt request (IRQ) line settings.

CAUSE

Default serial port settings are not updated properly from the information that is compiled with NTDETECT during the boot sequence. PCMCIA modems act as serial devices, thus they are not configured properly and may not function properly when used by an application such as Terminal.

WORKAROUND

To work around this problem:

1. Run Control Panel, choose Ports.

2. Select the communication port (COMx) that the PCMCIA modem or fax-modem is connected to and choose Settings.

3. In the Settings For COMx dialog box (where x is the communication port number), choose Advanced.

4. For the Base I/O Port Address, select the appropriate address for the COM port. For example, select 02F8 for COM2.

5. For the IRQ, select the appropriate IRQ for the COM port. For example, select 3 for COM2.

STATUS

Microsoft has confirmed this to be a problem in Windows NT version 3.51 And 4.0. We are researching this problem and will post new information here in the Microsoft Knowledge Base as it becomes available.