> It's roughly comparable to spending all R&D perfecting vacuum tubes in the 1940's Vacuum tubes continued to be improved all the way up into the early 1960s,

> It's roughly comparable to spending all R&D perfecting vacuum tubes in the 1940's Vacuum tubes continued to be improved all the way up into the early 1960s, long after transistors had taken hold: https://en.wikipedia.org/wiki/Compactron https://en.wikipedia.org/wiki/Compactron One in particular was used mainly in television sets, all the way up into the early 1970s: https://en.wikipedia.org/wiki/Nuvistor https://en.wikipedia.org/wiki/Nuvistor ...it competed with transistors, and was almost as small as some of its contemporary transistor cousins. Even today, you can't rule out the vacuum tube - for some things, there isn't any substitutes: http://www.nutsvolts.com/magazine/article/vacuum-tubes-for-the-21st-century http://www.nutsvolts.com/magazine/article/vacuum-tubes-for-t... ...and new ideas for the old technology are being investigated: http://www.sciencemag.org/news/2012/05/return-vacuum-tube http://www.sciencemag.org/news/2012/05/return-vacuum-tube