software that used the floating-point coprocessor, such as Windows Calculator, would allow users to discover whether their Pentium chip was affected. The correct value of the calculation is: When converted to the hexadecimal value used by the processor, 4,195,835 = 0x4005FB and 3,145,727 = 0x2FFFFF. The '5' in 0x4005FB triggers the access to the 'empty' array cells. As a result, the value returned by a flawed Pentium processor is incorrect at or beyond four digits: Discovery and response Thomas Nicely, a professor of mathematics at Lynchburg College, had written code to enumerate primes, twin primes, prime triplets, and prime quadruplets. Nicely noticed some inconsistencies in the calculations on June 13, 1994, shortly after adding a Pentium system to his group of computers, but was unable to eliminate other factors (such as programming errors, motherboard chipsets, etc.) until October 19, 1994. On October 24, 1994, he reported the issue to Intel. Intel had reportedly become aware of the issue independently by June 1994, and had begun fixing it at this point, but chose not to publicly disclose any details or recall affected CPUs. On October 30, 1994, Nicely sent an email describing the bug to various academic contacts, requesting reports of testing for the flaw on 486-DX4s, Pentiums and Pentium clones. The bug was quickly verified by others, and news of it spread quickly on the Internet. The bug acquired the name "Pentium FDIV bug" from the x86 assembly language mnemonic for floating-point division, the most frequently used instruction affected. The story first appeared in the press on November 7, 1994, in an article in Electronic Engineering Times, "Intel fixes a Pentium FPU glitch" by Alexander Wolfe, and was subsequently picked up by CNN in a segment aired on November 22. It was also reported on by the New York Times and the Boston Globe, making the front page in the latter. At this point, Intel acknowledged the floating-point flaw, but claimed that it was not serious and would not affect most users. Intel offered to replace processors to users who could prove that they were affected. However, although most independent estimates found that the bug would have a very limited impact on most users, it caused significant negative press for the company. IBM paused the sale of PCs containing Intel CPUs, and Intel's stock price decreased significantly. The motive behind IBM's decision was questioned by some in the industry; IBM