isham research
"We are not at all humble in this announcement. This is the most important product announcement that this corporation has ever made in its history. It's not a computer in any previous sense. It's not a product, but a line of products ... that spans in performance from the very low part of the computer line to the very high."
IBM spokesman at announcement of System/360
The System/360 announcement marked the beginning of the modern computing era. Although we recognise today the union of so many features - especially the separation of architecture from technology - most of us didn't at the time. System/360 was merely a "third generation machine", and as soon as it hit the floor the pundits started casting around for the fourth generation.
It's amazing to think that the majority employed in the IT industry today cannot remember the days before upward compatibility. They swap their Pentiums for Xeons without changing software - without realising that this was unthinkable for the first 30 years of commercial IT.
Computing had come a long way. At the very beginning, some companies even designed and built their own computers. Commercial machines tended to be special-purpose, with peripherals addressing specific tasks highly integrated into the system. The very concept of a "general purpose" machine was still quite new. System/360 emphasised its universality with the "360" part of the name - the number of degrees in a full circle. Early materials also had a compass logo on them.
But there's a powerful argument for saying that the System/360 announcement was actually NOT the most significant in the history of IBM's mainframes - the System/370 has a better claim.
Apart from some trivial (but useful) programmes like CONDCODE - often written as a programming exercise - the oldest major system known to be still running is the Wisconsin Department of Transportation's "File Handler". This is described as a "roll-your-own combination of DB2 and CICS" - even though it was written before either of them. It went live for the first time on 1 January 1974.