10-Key Adders
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10-key adders became popular in the mid 1950's, from a variety of manufacturers. This group includes adding machines of the portable design type with only a 10-key keyboard (modern calculator keypad).
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While the Burroughs 10-key (Series J) was a popular machine, it never had the success of the Burroughs Portable or the 10-key machines made by some of its competitors, like Victor. As one might expect, these machines were sold primarily to existing Burroughs customers, almost as an update to their older Burroughs adders.
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There were many models over the years built around the design of the first Series J machine. There were several multiplying versions such as the J 700 and the infamous (a nice looking machine that would run for about a month before breaking down) J 800 machine.
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In the 1960/70s, the machines were redesigned on the outside and given new plastic cases. Usually gray in color, but for a limited period of years the machines came in several pastels (blue, green, salmon, beige).
Interestingly, it is very difficult to find Series J machines. Perhaps because they were replaced with the new electronic calculators, they may have been perceived more as junk than antiques and simply discarded. It is more common to find older J machines like those pictured than the later models with the gray plastic cases.
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The basic mechanism for the Series J machines, a unique type bar/accumulator construction, was sold to several companies (as an assemble) for use in their products as the printing section. The J printing mechanism was selected after extensive reliability tests for high-speed printing.
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Series J – 10-key machines in the 200, 300, 400, 500, 600, 700, 800 model ranges
Date range -- 1954-1975
Original Price -- $100-$300
Today’s Value -- $50-$200
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Model J 214
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With the case off...
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My favorite, one of several color case machines (1950s) - they came in brown, blue, gray, green, and a funny tomato soup red.
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Series J machines were generally add and subtract only machines but there were several models
released at different times that had the ability to multiply. This machines is a J 700. It was the
most popular of all the Series J machines that could multiply.
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