I.B.M.'s six machines offer an alternative to the traditional mainframe, while Compaq's four computers are evidence of the microcomputer's growing role.

In contrast, traditional mainframes run on a single big processor that uses so much power and throws off so much heat it is water-cooled.

I.B.M.'s ability to convert its traditional mainframes into microprocessor-based parallel machines eventually helped to ensure the company's survival.

This kind of computing has had a significant impact on traditional mainframe and minicomputer markets because it permits faster and less-expensive operations.

The Y-MP2E is expected to appeal to customers trading up from minisupercomputers and traditional mainframes.

The first version of that system may be introduced as early as next month, and a full replacement for the traditional mainframe is expected to appear sometime in 1994.

On traditional mainframes, the classic type 1 hypervisor was self-standing and did not depend on any operating system or run any user applications itself.

The acquisition was completed just as many customers came to realize that Year 2000 problems extended well beyond the traditional mainframes.

The migration of work from traditional mainframes is also forcing change.

Because the flight from the traditional mainframe is now irreversible, and the central repository of the future will be something new.