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Friden Model SBT 10

Friden Model SBT 10

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Usage conditions apply
This modification of Friden’s fully automatic STW calculating machine allows for “back transfer.” That is to say, it has a mechanism to transfer figures from the accumulator register to the keyboard selecting levers and vice versa. The model was manufactured from 1959 until 1965.
The full-keyboard electric non-printing stepped drum machine has a metal frame painted tan and ten columns of brown and white plastic keys, with a blank white key at the bottom of each column. Metal rods between the columns of keys and under the keyboard turn to indicate decimal points. On the right are two columns of function bars. On the left is a nine-digit register that indicates numbers entered for multiplication. Below it is a block of nine white digit keys, with a 0 bar below. These are surrounded by further levers and function keys, including a split “NEG POS TRANSFER” bar.
Behind the entry keys is a movable carriage with an 11-digit register and a 20-digit result register. The result register has plastic buttons above it that can be used to set up numbers. Nine entry buttons and a clear button are under the revolution register. Zeroing knobs for the registers are on the right of the carriage. A clear carriage bar is toward the front of the keyboard. All three registers have sliding decimal markers. The machine has four hard rubber feet as well as a rubber cord and a tan plastic cover.
A mark on the bottom reads: MODEL SERIAL (/) SBT 10 907698. A mark on the back and side reads: Friden. A sticker on the bottom reads: FRIDEN, INC. (/) SAN LEONARDO, CALIFORNIA, USA. A mark on the cover reads: Friden (/) AUTOMATIC CALCULATOR.
For related documents, see 1984.0475.02, 1984.0475.03, 1984.0475.07, and non-accession 1984.3079.
This is one of five Friden calculating machines given to the Smithsonian by Vincent L. Corrado (1917-1984), a native of Covington, Kentucky, who earned bachelor’s and master’s degrees in accounting at Catholic University, served in the U.S. Army from 1942 through 1973, and then joined the Veteran’s Administration for the rest of his life.
The date given is based on the serial number, courtesy of Carl Holm. This is the date of manufacture.
Ernie Jorgenson, Friden Age List, Office Machine Americana, p. 5 gives the date 1960 for this machine.
Currently not on view
Object Name
calculating machine
date made
Friden, Inc.
place made
United States: California, San Leandro
Physical Description
metal (overall material)
plastic (overall material)
rubber (overall material)
overall: 25 cm x 50 cm x 30 cm; 9 27/32 in x 19 11/16 in x 11 13/16 in
ID Number
catalog number
accession number
maker number
SBT 10 907698
Credit Line
Gift of Vincent L. Corrado
See more items in
Medicine and Science: Mathematics
Science & Mathematics
Calculating Machines
Data Source
National Museum of American History
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The headline for this page has the incorrect model designation - it should read "SBT " not "SHT ". Refer to the "Maker Number " field on this page which shows the serial number beginning with SBT.

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