By William Fellows
Another chapter in the mainframe book has been closed with the news that Hitachi Ltd has seen the point at which CMOS overtakes its bi-polar ECL mainframe technology and says it will converge the two over the next few years. It’ll be a graceful exit from the venerable chip technology which Hitachi has milked very well with its Skyline series mainframes. Hitachi says it’s unlikely to produce a mixed instruction set but will converge the base technologies at least to the point where the CPUs will present a common interface to the back-end. The geometry of CMOS overtakes the benefit of the hybrid chip, it admits. It will have plenty of opportunity to fuse the two as IBM Corp has decided that from the end of this year it will no longer OEM the CMOS chipset technology used in its G Series S/39 mainframes to the plug- compatible vendors. Hitachi Ltd will take over development of its own CMOS architecture. Hitachi wouldn’t say how many more generations of Skylines it will create but clearly it has almost reached the point where it loses more than it gains with each iteration.