Search results
Results from the WOW.Com Content Network
A pinwheel calculator is a class of mechanical calculator described as early as 1685, and popular in the 19th and 20th century, calculating via wheels whose number of teeth were adjustable. These wheels, also called pinwheels, could be set by using a side lever which could expose anywhere from 0 to 9 teeth, and therefore when coupled to a ...
Odhner thought of his machine in 1871 while repairing a Thomas' Arithmometer (which was the only mechanical calculator in production at the time) and decided to replace its heavy, bulky Leibniz cylinder by a lighter, smaller pinwheel disk. This is why the two machines share the same name but look completely different.
The Leibniz wheel was used in many calculating machines for 200 years, and into the 1970s with the Curta hand calculator, until the advent of the electronic calculator in the mid-1970s. Leibniz was also the first to promote the idea of an Pinwheel calculator .
The gift of a Texas Instruments calculator opened a new world of math problems and secret codes in the years ... Calculator was fun for a math phobic kid in the 1970s. Show comments. Advertisement.
In about 1970 HP co-founder Bill Hewlett challenged France Rode to create a "shirt-pocket sized HP-9100".At the time, slide rules were the only practical portable devices for performing trigonometric and exponential functions, as existing pocket calculators could only perform addition, subtraction, multiplication, and division.
Despite the mechanical flaws of the stepped reckoner, it suggested possibilities to future calculator builders. The operating mechanism, invented by Leibniz, called the stepped cylinder or Leibniz wheel, was used in many calculating machines for 200 years, and into the 1970s with the Curta hand calculator.
ANITA Mk VIII. The ANITA Mark VII and ANITA Mark VIII calculators were launched simultaneously in late 1961 as the world's first all-electronic desktop calculators. [1] [2] Designed and built by the Bell Punch Co. in Britain, and marketed through its Sumlock Comptometer division, they used vacuum tubes and cold-cathode switching tubes in their logic circuits and nixie tubes for their numerical ...
SR-50 (1974) Printed circuit board. Data code 035: 3rd week 1975. The SR-50 was Texas Instruments' first scientific pocket calculator with trigonometric and logarithm functions. . It enhanced their earlier SR-10 and SR-11 calculators, introduced in 1973, which had featured scientific notation, squares, square root, and reciprocals, but had no trig or log functions, and lacked other featur