In the early twentieth century a variety of companies manufactured full keyboard adding machines that competed with the products of Felt & Tarrant and of Burroughs. Their inventors often had ties to one …

While all adding machines could be transported, this group consists of a much lighter machine type released in the 1920's. This group of adding machines of the portable design were called "full …

It has a full keyboard with 7 columns. If you enter a number on the keyboard and pull the large lever, the number is printed and gets added to the internal register, and the keyboard input is cleared …

In the 1950s, Burroughs abandoned manufacture of full keyboard adding machines in favor of ten-key devices built on patents of the British Summit adding machine. Burroughs Corporation inventors …

While considered adding machines, all the models pictured in this section had some feature for making multiplication a reasonable chore. On the machines above, after entering one factor, a …

William S. Burroughs (1855-1898) invented an adding and listing machine with a full keyboard in the early 1880s, submitted a patent application in 1885, co-founded the American Arithmometer Co. in …

In general, the Adding Machine mode of operation died out among electronic calculators, but persisted in calculators designed for use in offices where people were more used to it, as with the Decimo …

This full-keyboard printing electric adding machine has a steel mechanism, a carriage, a keyboard with red, black and white plastic keys, a handle, and a paper tape holder.

This group includes adding machines of the portable design type with only a 10-key keyboard (modern calculator keypad). While the Burroughs 10-key (Series J) was a popular machine, it never had the …

Such so-called full keyboard machines were made and sold by several American manufacturers, most notably the Burroughs Adding Machine Company of Detroit and the Felt & Tarrant Manufacturing …