S3 Video Driver Conflicts with COM4

• Microsoft Windows 95

SYMPTOMS

When you are using a modem on COM4 in Windows 95, the modem lights may flash when you move the mouse or when there is any disk or network activity.

CAUSE

Some of the older video chip sets by S3 decode the x2E8 address range incorrectly with the I/O address mapping performed in Windows 95. These chip sets include the 801, 805, and 928 versions.

The following video cards are known to cause this behavior:

• Diamond Stealth 32
• Diamond Stealth 64
• Orchid Technology Fahrenheit 1280
• S3 video cards (most models)

RESOLUTION

To correct this behavior, use any one of the following methods:

• Contact S3 about an address change.
• Change the port your modem is using to another available COM port.
• Use a Windows version 3.1x S3 video driver.

  Note that when you use a Windows 3.1x video driver in Windows 95, you lose some Windows 95 functionality (such as animated mouse pointers, mouse trails, and fallback video support).

• Change your video resolution to 256 colors or less and set the hardware acceleration slider to None.

  For information about how to use the slider to change the way Windows 95 uses the video card, please see the following article in the Microsoft Knowledge Base:

        ARTICLE-ID  :  Q127139
        TITLE       :  Troubleshooting Video Problems in Windows 95
  
  

MORE INFORMATION

This problem may not occur with the 964/984, trio/64/32, or 866/868/968 chip sets and does not occur with any newer chip sets released by S3.