Scott Stevens wrote: <snip> No argument about there being ICs and core. I only pointed out the time frame wasn't long. The first core machine I remember seeing was the 1103 and it used vacuum tubes. (1K by 36 bits). Using it as a reference up to the last Cray designs with core and transistors, there is a long time frame, at least 2 decades . Core and ICs made the transition. But with ICs came the 1101, then the 1103. After that, RAM exploded and it was a rare machine that stayed with core for very long. Core died quickly, relative to it's life span. Core is still used in a few applications, mainly space. But another technology made most of the early trips to the planets, a variation of core called plated wire. Some of those are 30+ years old and still haven't dropped a bit! And then there are the EMP hardened technologies that still can't be discussed, even today. Billy