from
The Free On-line Dictionary of Computing (8 July 2008)
portable computer
laptop
laptop computer
<computer> (Commonly, "laptop") A portable {personal computer}
you can carry with one hand. Some laptops run so hot that it
would be quite uncomforable to actually use them on your lap
for long. The term "notebook" is often used to describe
these, though it also implies a low weight (less than 2kg). A
"{luggable}" is one you could carry in one hand but is so
heavy you wouldn't want to. One that can by easily operated
while held in one hand is a "{palmtop}".
The computer considered by most historians to be the first
true portable computer was the {Osborne 1} but see the link
below for other contenders.
History of laptop computers
(http://inventors.about.com/library/inventors/bllaptop.htm).
(2007-05-21)