Microsoft KB Archive/29597

Knowledge Base

Works: Avoiding a Communication Interrupt Conflict

Article ID: 29597

Article Last Modified on 11/16/2006

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APPLIES TO

• Microsoft Works 3.0 for MS-DOS
• Microsoft Works 3.0 Standard Edition
• Microsoft Works 4.5 Standard Edition
• Microsoft Works 4.5a
• Microsoft Works 4.0 Standard Edition
• Microsoft Works 4.0a

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This article was previously published under Q29597

SYMPTOMS

If both your modem and another device on the system are using the same COM port or different COM ports but the same interrupt (IRQ), the following problems may occur when you try to dial or connect:

• The modem may not dial or connect.
• The system may stop responding (hang).
• The mouse pointer may freeze momentarily or until you restart your machine.
• The machine may exit to an MS-DOS prompt or to a flashing cursor.

RESOLUTION

To correct the problem, check the following:

1. Make sure there are no other hardware devices using the same interrupt as the modem:

   COM1 and COM3: IRQ4
   COM2 and COM4: IRQ3

   If there is another device, such as a mouse, trackball, digitizer tablet, scanner, fax card, net card, or sound card, using the same interrupt, either change the interrupt of the modem or the other device, or remove the other device from the system.
   
   

   For information about how to change the interrupt of the modem or other device, see the documentation for the device or contact the manufacturer. The method used to change the interrupt depends on the device because it may be a jumper, a DIP switch setting, or software.

2. Make sure that the IRQ setting on the modem matches the selected COM port. For Works for MS-DOS, COM1 and COM3 should be set to IRQ4, and COM2 and COM4 to IRQ3. For Works for Windows, the Windows Control Panel setting for the port must match the IRQ setting on the modem. Follow the steps for your version of Windows to check the IRQ setting:

   Under Windows 95

   1. Click on Start, and point to Settings, and click on Control Panel.
   2. Click on the System icon.
   3. Click on Device Manager.
   4. Select View Devices By Type.
   5. Click on the PLUS (+) by Ports(COM & LPT).
   6. Click on the Communications Port used by the modem.
   7. Click on Properties, then click on Resources.

   Under Windows 3.0

   1. Click the Control Panel icon in the Main group in Program Manager.
   2. Click the Ports icon.
   3. Click the port used by the modem.
   4. Click on Settings, then click on Advanced.
3. Notebook/Laptop PCs that power-down serial ports to save power must disable this feature. The power-down serial port automatically turns off the power to the serial port.

For more information about system hangs when using the Communications module, query on the following:

124367 Works Troubleshooting Duplicate COMx Port Problems

For Works for Windows, query on these additional articles:

111345 System Hangs in Communications, Dial This Number, or Tools

117349 Works 3.0: Using DisablePortChecking to Resolve IRQ Conflicts

Additional query words: 2.00 4.00 4.00a 4.50 4.50a w_works d_works Tools Options Hang

Keywords: kbprb KB29597

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