Graphing calculator electrical power line transmission. Casio produced the first commercially available graphing calculator, the fx-7000G, in 1985. Casio's innovations include an icon menu for easy access to functions (1994, FX-7700GE and later), graphing in several colors (1995, CFX-9800G), textbook-like "Natural Display" input and output (2004, FX-82ES/300ES & FX-9860G), expandable memory (2005, FX-9860SD), backlit screen (2006, FX-9860G Slim), full-color, high resolution backlit screen (2010, FX-CG10/CG20 PRIZM). Sharp produced its first graphing calculator, the EL-5200, in 1986. Since then Sharp's innovations include models with a touchscreen (EL9600 series), Equation Editor (textbook-like input) (EL-9300 ( 1992 ) and later), and reversible keyboard to ease
Mechanical calculator as tax collector in Rouen, Pascal designed the calculator to help in the large amount of tedious arithmetic required; it was called Pascal's Calculator or Pascaline. Thomas' arithmometer, the first commercially successful machine, was manufactured two hundred years later in 1851; it was the first mechanical calculator strong enough and reliable enough to be used daily in an office environment. For forty years the arithmometer was the only type of mechanical calculator available for sale. The comptometer, introduced in 1887, was the first machine to use a keyboard which consisted of columns of nine keys (from 1 to 9) for