I have heard two wives' tales regarding the origin of this CD-ending device. One involves a man who was working with a Magnetron and he noticed that a candy bar had melted in his pocket (this of course having nothing to do with the standard M&Ms claim). Through various other discovery, he managed to put this heating aspect of microwaves to good use. The other story being a more colorful tale about a How the Potatoe Delayed the microwave 10 years, (How the Potato Delayed the Microwave 10 years)

Several facts however remain undisputed: First, they were very unpopular at their beginnings out of Raytheon. They were used in commerical cooking applications early on (they were referred to then as a Radio Range), with several diners using this new invention as a primary cooking device. My grandmother used to tell stories about such (and while they are not 100% accurate, the color of them is more than enough to make up for some fudge here and there). The first units (as my friend likes to call his older microwave "the lead apron kind"), were huge and bulky. They started off in Boston, Massachusetts (where Raytheon is located), and spread from there. These stories came to me from residents of that area around that time, and the children of the Raytheon engineers on that project.