Two weeks ago the Internet was buzzing with reports about the F0 bug, a new microprocessor flaw that could cause Pentium and Pentium MMX PCs to crash. But for various reasons, the bug now no longer seems to be of much concern to Intel Corp. or Microsoft Corp.
According to sources close to Microsoft, the company has decided not to implement an operating
system fix for the F0 bug. That was the solution that Intel and Microsoft worked out soon after Intel
acknowledged the flaw, which it calls the "invalid instruction erratum." But a source inside Microsoft's
support operation says the company has closed the trouble ticket on the F0 bug, which means it plans
no further action on a patch that would protect Pentium-based Windows machines.
Microsoft officials couldn't be reached to confirm this report, but previously Microsoft and Intel have
pointed out that the bug isn't triggered by commercial software -- only by malicious programs written
to exploit the bug. In a statement on Intel's Web site, a Microsoft vice president says users can avoid
the problem by not downloading or running programs from unknown sources.
But that solution doesn't sit well with some administrators of Pentium-based servers, who may not be
able to control what code is executed on their multi-user machines. Nor did it satisfy Jim Finnegan, a
Windows systems programmer and contributing editor to Microsoft System Journal. Rather than
waiting for Microsoft to offer a patch for Windows, he wrote his own, and has made a beta version
available for free on the Internet. Finnegan says the patch works on both Windows 95 and Windows
NT systems; it is manually loaded at run time.
"If something has this invalid code in it, [the patch] will generate an exception ... which will be
displayed by the exception handler under 95 or NT [giving the user the chance to quit the program]."
Finnegan says he's hoping to create a version of P5Fix that becomes a system-tray application, giving
users the ability to turn the program on and off.