IBM Hexadecimal Adder / Adding Machine
Item History & Price
| Reference Number: Avaluer:13526 | Maker: Sterling Plastics Co. |
This is a dial-type adding machine that adds and subtracts in hexadecimal. The US patent number on the back, 2, 797, 047, refers to a 1957 patent by Otto Lehre of Springfield, New Jersey. The patent concerns the mechanism of the adder and makes no mention of hexadecimal arithmetic. In fact, it specifically mentions that the wheels will be marked 0 through 9, with both addition and subtraction digits. Lehre assigned the patent to Sterling Plastics, of Union, New ...Jersey, a company that made many plastic dial-type adders (under the “Add-It” or “Dial-a-Matic” model names), and almost certainly made this one for IBM. The same patent number is also found on Sterling-branded adding machines.
This adder is in great condition. There are a few insignificant scratches and abrasions, none of which are visible unless the light is from just the right angle. Unlike most Sterling adders, which were made of a soft, flexible thermoplastic, the IBM hex adder is made of a hard thermoset plastic. Although this one is showing no signs of becoming brittle with age, I chose to not tempt fate and only tested single-column carries, not multi-column. It works perfectly. The original stylus, which stores in a slot in the end of the adder, is included.
This adding machine is from the collection of Robert K. (“Bob”) Otnes, PhD, one of the founding members of the Oughtred Society and the original editor of the Journal of the Oughtred Society. It is being sold by the Oughtred Society on his behalf.
The Oughtred Society was founded in 1991 by a group of slide rule collectors and is dedicated to the preservation and history of slide rules and other calculating instruments. Membership is open to anyone. Further information about the Oughtred Society can be found at: http://www.oughtred.org/.
PayPal is the only accepted form of payment. Buyers within California will be charged 7.25% sales tax.
Shipping will be by USPS Priority Mail. Shipping charges will be somewhat higher for destinations outside the USA.
This adder is in great condition. There are a few insignificant scratches and abrasions, none of which are visible unless the light is from just the right angle. Unlike most Sterling adders, which were made of a soft, flexible thermoplastic, the IBM hex adder is made of a hard thermoset plastic. Although this one is showing no signs of becoming brittle with age, I chose to not tempt fate and only tested single-column carries, not multi-column. It works perfectly. The original stylus, which stores in a slot in the end of the adder, is included.
This adding machine is from the collection of Robert K. (“Bob”) Otnes, PhD, one of the founding members of the Oughtred Society and the original editor of the Journal of the Oughtred Society. It is being sold by the Oughtred Society on his behalf.
The Oughtred Society was founded in 1991 by a group of slide rule collectors and is dedicated to the preservation and history of slide rules and other calculating instruments. Membership is open to anyone. Further information about the Oughtred Society can be found at: http://www.oughtred.org/.
PayPal is the only accepted form of payment. Buyers within California will be charged 7.25% sales tax.
Shipping will be by USPS Priority Mail. Shipping charges will be somewhat higher for destinations outside the USA.
