Rich said; >it (i.e., the vacuum-tube) would be hailed as a techological >breakthrough. Something similar has been said about pencil and paper as a wondrous new non volatile low power storage medium! Many years ago, I worked for a guy who said that if you couldn't do it with a twin triode, it wasn't worth doing. He did allow pentodes and beam power tubes as well! 73 Peter G3RZP