Apple Computer Set to Unveil Beta Version of Its Long-Awaited Operating System.

Byline: Jon Fortt

Sep. 13--Since Steve Jobs took charge at Apple Computer Inc. in 1997, the trains have been running on time -- Apple has thrilled customers and investors, introducing the colorful line of iMac computers, streamlining inventory management and boosting profits. But there's one notable exception.

There is a major project at Apple that has continued to run behind schedule: the rollout of OS X, an updated operating system that Apple promises will set the standard for consumer PC stability and bring Apple's reputation for ease of use into the new millennium.

"This is a necessary and very important step forward for Apple," said Chris LeTocq, analyst with Gartner Group. "They've essentially been resting on what was created in 1984, 16 years ago -- that's a long time for an operating system."

Indeed, OS X is late, even for the …