Larry Smarr presented this talk as part of NCSA’s 30th Anniversary Celebration. “For the last thirty years, NCSA has played a critical role in bringing computational science and scientific visualization to the national user community. I will embed those three decades in the 50 year period 1975 to 2025, beginning with my solving Einstein’s equations for colliding black holes on the megaFLOPs CDC 6600 and ending with the exascale supercomputer. This 50 years spans a period in which we will have seen a one trillion-fold increase in supercomputer speed.”