The Pentium division Flaw - Chapter 8

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CHAPTER 8:    HOW TO TEST FOR THE PENTIUM BUG.

SIMPLE HAND TEST:
In the Microsoft windows calculator try 5506153/294911

Correct: 18.67055823621
Pentium: 18.66990719234

If you get the incorrect answer then you definitely have the bug. If you get the correct answer then either you have the newer Pentium chip with the bug corrected, or you have a calculator which is "Pentium aware". "Pentium aware" software looks for and catches any incorrect division result caused by the bug and recalculates the result using some other method so you still get the right answer.


CPU ID PROGRAM:
The only sure way to determine if your CPU does or does not have the FDIV flaw is to identify the CPU's family, model, and stepping, and compare that against a list of ones known to have the bug. Pentium chips have a special instruction, CPUID, which returns chip identification information. Intel has an official program which uses the CPUID instruction to identify CPU chips, including which ones have the FDIV bug. The program is available at:

ftp.intel.com:/pub/IAL/pentium/cpuidf.exe - executable
ftp.intel.com:/pub/IAL/pentium/cpuidf.txt - instructions

World Wide Web (http://www.intel.com under Pentium)
CompuServe (GO: Intel)
America On-Line (Keyword:Intel)





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