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
Calculator and built at the Elektronika factory in Sofia. The name derives from "ELektronen KAlkulator", and it weighed around . It is the first calculator in the world which includes the square root function. Later that same year were released the ELKA 22 (with a luminescent display) and the ELKA 25, with an in-built printer. Several other models were developed until the first pocket model, the ELKA 101, was released in 1974. The writing on it was in Roman script, and it was exported to western countries. The "Monroe Epic" programmable calculator came on the market in 1967. A large, printing,