from
The Free On-line Dictionary of Computing (8 July 2008)
IBM 370ESA
IBM390
IBM zSeries
<computer, IBM> (Enterprise System Architecture) An {IBM}
{mainframe} {computer} introduced in 1988. Successor to the
{IBM 370XA} had enhanced access registers that allowed access
to other forms of virtual memory. This enhancement allowed
more data storage in main and virtual memory, reducing {I/O}
operating and improving speed and efficiency. The IBM 370ESA
was rebranded as the IBM390, and later as the zSeries.
(2004-06-06)