Unisys has confirmed it will phase out the CMOS processors in its ClearPath mainframes and enable its MCP and OS 2200 operating systems to run on Intel-based hardware.

The company first broached the possibility of abandoning traditional mainframe CMOS technology last autumn, after agreeing to collaborate with NEC on the development of high-end servers built around Intel's Xeon processors. The company will move gingerly on a transition which is a major change for users.

Unisys' first Xeon-based ClearPath hardware is due in late 2007, and will run Linux and Windows, as well as the MCP and OS 2200 operating systems. But the vendor isn't setting an end-of-life date for the internally developed CMOS processors or ruling out future upgrades.

"We continue to reserve our options," said Colin Lacey, vice president and general manager of the company's enterprise server business unit.

Lacey added, though, that the expected performance growth of Intel's multicore Xeon chips leaves "no specific reason to carry forward on a unique processor" design.

"This is a drastic change for the 2200 and MCP customers," said Greg Schweizer, a systems administrator and ClearPath user at Oregonian Publishing. "But knowing the quality control that Unisys has always had in testing, I wouldn't expect them to release [the Intel-based hardware] until they are confident that it is bug-free."

Kevin Kelly, who does software support on systems running OS 2200 at the Virginia Information Technologies Agency in Richmond, said he has questions about the reliability, cost and processing power of the upcoming Intel-based machines. "I don't know what it means in terms of performance," Kelly said.

But Marian Ritland, development and operations manager at the University of Wisconsin-Eau Claire, said she supports the Unisys plan. The school runs its core academic applications on a ClearPath system with MCP. Unisys' adoption of Xeon gives Ritland "good, solid reasons why continuing with [the MCP] environment makes business sense," she said. "It makes it a little easier to convince upper management that Unisys is a viable long-term strategy and not something to be migrated off of."

Ritland, who also is chairwoman of the Unite user group in St. Clair Shores, Minnesota., said that many MCP users run custom-built applications and don't want to leave that operating system behind because of its reliability and security. She added that the move to Intel CPUs will make it easier for Windows and MCP applications to work together in shared environments, which Ritland sees as a plus.

Unisys, which already uses Intel processors on some of its low-end and midrange ClearPath systems that run MCP, will continue to develop the two mainframe operating systems. Firmware will sit between the Xeon processors and the operating systems, allowing users to run their applications on the Intel-based hardware without any alterations, according to Lacey.

He said that users will be able to easily move their applications to the new hardware. "This is a plug-and-play solution, from a customer perspective," Lacey said