I was once told that when System 360 replaced the 70XX series, without any upward compatibility, forcing every existing program to be recompiled, Thomas Watson Jr was required to personally reassure the government infrastructure this would never happen again.  Hence the systems world was forced to accept Evolutionary changes and do without any of the Revolutionary changes that were proposed since that time.  Can anyone add any information that supports or discredits this aspect of TechnologyStasis?

''Discredits. Emulators were really big back then for exactly this kind of thing. It was before my time, so I double-checked my memory; here's one reference:'' http://www.tbray.org/ongoing/When/200x/2004/04/12/FowlerOnIBM

''I had an instructor who talked about all this sort of thing, and he claimed that he once dealt with a company that had gone through this 7 times, being persuaded to upgrade to new hardware by being given an emulator for their old hardware -- so that they literally had 7 levels of emulators, still running some circa 1955 accounting package, very slowly because of all the emulators, despite having upgraded to a top of the line IBM mainframe. Maybe he was just making a point, maybe he exaggerated, but it's kind of believable that at least one company would do something dumb like that.''

Thanks for the great reference, Doug.