The executable file in this archive, CYRIXS.EXE, will detect the bug in the Cyrix Cx486DX that was discovered during testing at Lone Star Evaluation Labs (LSEL) in Georgetown, Texas. This bug affects only the Cx486DX.  It does NOT affect any other Cyrix products such as the Cx486DLC or the Cx486DRx2.

LSEL and Windows Magazine testing indicate that this bug is most likely to occur in 32-bit OS/2 or Windows NT programs that use floating-point instructions. Because of the way that compilers generate code for 16-bit Windows 3.1 applications, it is unlikely that you would encounter the bug while running the shrink-wrapped software applications available today.  For more information about the bug, see the news article in Windows Magazine, May 1994, page 26.

CYRIXS is a Windows 3.1 application that tests for the existence of the Cx486DX floating-point bug.  To run the program, select the File/Run menu in Program Manager, click the Browse button, find CYRIXS.EXE (in the directory you un-zipped this archive in), and click OK.  The program will display a dialog box that indicates whether it detected the bug, and then exit when you click the OK button.  The dialog box is the program's only output.

If the test indicates that your system is exhibiting the bug, you may wish to contact Cyrix tech support at 800-462-9749. The Cyrix technician may ask for the numbers on the top of the CPU chip (which represent a coded manufacturing date and location); you may save yourself time by copying down these numbers beforehand.

Tests done at Windows Magazine showed that CYRIXS.EXE was able to detect the bug in the chip and system board we had available to us.  However, there may be circumstances where it does not detect the problem.  If you have any doubt whether your Cx486DX-based system has this bug, call Cyrix at the number given above.  Please remember that the bug only affects the Cx486DX, and that the Cyrix support staff will need you to obtain the date code numbers from the top of the chip to determine if the chip has the bug.

Because we offer this tool for free, we cannot provide personalized advice or technical support: Please do not call us with specific questions about your system. This test is distributed as freeware, but is Copyright (C) 1994 by  CMP Publications, Inc. All rights reserved. You may freely use, copy, and redistribute  the software as long as you include all the original files, and as long as you make no changes to the contents of the original files.

Disclaimers: We have taken  great pains to make this software as good as we can. However, we cannot and do not guarantee it will work properly on all systems all the time, and therefore offer the software "as-is" without warranty or guarantee as to merchantability or suitability to task. You use this software at your own risk.

If you aren't sure of the suitability to task of the software on this disk, or are uncertain about your ability to use it properly, seek additional advice before proceeding. In any case, CMP Publications, Inc., its employees or freelancers are not responsible for any injury, damage, or loss resulting from your use of this disk or the software or information it contains.