November 14, 2015:  Gene Amdahl,   the 'father'   of the IBM  System/360   -- arguably the most  widely used  mainframe computer in the world --  has  passed away.  He died  of pneumonia  and Alzheimer's disease on November 10, in a nursing home in Palo Alto California, at the age of 92.
Coincidentally, it is 50 years ago that the first machine in the  System 360 family of computers  was first shipped by IBM. It was the Model 30,  and could perform up to 34,500 instructions per second, with memory from 8 to 64 KB.   System /360  was the biggest  seller for IBM and continued to be delivered till about1978, though System/370 had made its appearence in 1970.
Dr Amdahl was the Chief Architect of System/ 360. 
The New York Times  in its obituary  story  quotes Michael J. Flynn, a computer scientist at Stanford University and former colleague of Dr. Amdahl’s at IBM:  "(The 360 series) set the design philosophy for computers for the next 50 years, and to this day it’s still out there, which is incredible....This same instruction set is still bringing in billions of dollars for IBM.” IBM’s current mainframes can still run some System/360 applications.
In 1970,  Dr  Amdahl  left IBM to build  his own company   to take on IBM in mainframes. With funding from Fujitsu, he formed the Amdahl Corporation to  build computers  compatible  with IBM's  System/370, but cheaper and faster. He  cannily named it the 470 series and shipped the first machine, in 1975.  By 1979, Amdahl had  grabbed 22 percent of the mainframe market.  The company was  bought out by Fujitsu in 1997.

Dr Amdahl is also known for Amdahl's law,  which is used to find the maximum expected improvement to an overall system when only part of the system is improved. It is often used in parallel computing to predict the theoretical maximum speed- up using multiple processors.
Dr. Amdahl   tasted failure in his next venture -- Trilogy Systems, which he  started after leaving Amdahl in 1979,  to build  an IC  that would allow mainframe manufacturers to build computers at lower costs.  It never happened.

But till today, his reputation  as one of the world' s  greatest computer architect remains undiminished. IndiaTechOnline  salutes the memory of Gene Amdahl, Bhishma Pitamah  of the mainframe computer.