I was wondering how long laptop computers have existed. The Epson HX-20 (1981) and Grid Compass (1982) seem like good early examples - the latter introducing th

I was wondering how long laptop computers have existed. The Epson HX-20 (1981) and Grid Compass (1982) seem like good early examples - the latter introducing the clamshell design used in many subsequent laptops such as ThinkPads.