Windows Programs Rely on BIOS to Detect Coprocessor (82575)


The information in this article applies to:

  • Microsoft Windows 3.0
  • Microsoft Windows 3.0a
  • Microsoft Windows 3.1
  • Microsoft Windows 3.11
This article was previously published under Q82575

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.
Modification Type:MinorLast Reviewed:7/7/2005
Keywords:KB82575
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