Windows Programs Rely on BIOS to Detect Coprocessor

 Last reviewed: November 22, 1994
Article ID: Q82575
The information in this article applies to:
  • Microsoft Windows operating system versions 3.0, 3.0a, 3.1, 3.11

SUMMARY

Strange behavior with applications that use math coprocessors (Microsoft Excel, for instance) can be due to the BIOS reporting the presence of a math coprocessor when one does not exist. For example, if you have a 486SX machine with a BIOS designed for a 486DX and you type a number in Microsoft Excel, an incorrect floating-point number is displayed.

MORE INFORMATION

Windows issues an INT 11h (equipment check) function call to determine whether a math coprocessor is present.

Do the following to determine test whether there is a coprocessor detection problem on a computer:

  1. Run Microsoft Diagnostics (MSD).

  2. Choose the Computer option.

  3. If a coprocessor is detected, and the machine does not have one, the BIOS will need to be replaced with a BIOS that does not incorrectly report a non-existent coprocessor.

KBCategory: kbhw kbdisplay kbprb
KBSubcategory: win31 win30
Additional reference words: 3.10 3.11 3.00 3.00a excel

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Last reviewed: November 22, 1994
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