Most recent reference is 1991 with many from 1990. I think it is safe to say (1991).<p>Edit: includes an internal reference to &quot;late 1991&quot;, so maybe (1992) or (1993) is more accurate.<p>Edit2: and you were right (1993). Citation: Boelie Elzen and Donald MacKenzie, &quot;From Megaflops to Total Solutions: The Changing Dynamics of Competitiveness in Supercomputing,&quot; in Technological Competitiveness: Contemporary and Historical Perspectives on Electrical, Electronics, and Computer Industries (Piscataway, NJ: IEEE Press, 1993), 119-151.