K6-2, Windows 95 mismatch cured

The mismatch occurred when the Windows 95 operating system was run on K6-2 processors running at 350 MHz.

Michael Kanellos Staff Writer, CNET News.com
Michael Kanellos is editor at large at CNET News.com, where he covers hardware, research and development, start-ups and the tech industry overseas.
Michael Kanellos
2 min read
A relatively obscure, but annoying, glitch has been discovered when the fastest versions of the K6-2 processor from Advanced Micro Devices is used in conjunction with Windows 95, but the company and Microsoft have taken steps to eradicate it.

The flaw occurs when Windows 95 is run on 350-MHz K6-2 processors, according to AMD. Essentially, when a user attempts to boot up, the computer replies that a "Windows Protection" error has occurred and that the computer must be rebooted. Typically, the flaw does not repeat itself on the reboot.

The flaw only manifests itself intermittently and comes as a result of a mismatch between processor frequency and the software timing loop. The problem is not an inherent flaw to the processor.

In fact, the problem resides in Windows 95, according to Microsoft engineers, although it manifests itself only on certain processors. A similar problem was discovered with the 333-MHz Pentium II, but the problem was discovered and cured before the release of the chip. The incompatibility with the K6-2 was not discovered until recently.

"Basically, the speed of the processor was too fast," said a spokesperson at AMD.

The flaw does not appear on computers running Windows 98 or Windows NT, the spokesperson added. Major domestic computer vendors are bundling their AMD systems with Windows 98.

Computers affected by the flaw are generally from overseas vendors or regional dealers. The flaw can also affect consumers who build their own systems. The 350-MHz K6-2 was released in late August. As a result, few systems are affected, said Michael Steel, an AMD product manager.

A patch for the bug developed by Microsoft was posted late last week. To get the patch, users are told to contact Microsoft's support lines and request the "hotfix for Windows 95." The call is free but customers will be charged $35 for the support incident, according to an update on AMD's Web site. More on fixing the flaw can be found at a bulletin on AMD's Web site.

Users need to use Windows 95 release 2.1 and the patch to eliminate the problem, Microsoft sources said.

AMD has known about the flaw since the release of the 350-MHz K6-2, and has been working on a patch since then. Typically, AMD does not post information on processor flaws until a fix is found, said sources.

Later this year, 380 MHz and 400 MHz versions of the AMD chip are due.