IBM

It is fair to say that after the dreams of Sir Charles Babbage had long since passed, nobody really wanted a mechanical adding machine to calculate logs and tables - which human Computers had done for millennia. That was until New Yorker and MIT instructor Herman Hollerith invented a punch card machine to tabulate the 1890 National Census, based apparently on the way attendants on the railroads punched tickets to verify the passengers. The Hollerith Electric Tabulating System became The Computing-Tabulating-Recording Company, and later "International Business Machines" in 1917.

After the first world war, and after they saw ENIAC and UNIVAC, IBM released the 701 in 1953, which was known as the "Defence Calculator"; which took up an entire room, and only 19 were produced. A long series of adding machines followed, each becoming heaver and more expensive than the last; with each having about as much computing power as a modern cash register.

The IBM 5110 was released in 1978, a 'portable' computer, which weighed in at nearly 20 kilograms. It required a very sturdy desk.