Image Caption: A Casio FX-7000G with box and manual. Credit: ML5/Wikipedia
The Casio FX-7000G is the world’s first graphing calculator available to the public, offering 82 scientific functions, the ability to produce graphs, it is programmable and can do basic arithmetic problems. It was manufactured from 1985 – 1988. Since then Casio has produced upgraded models using the same technologies.
The functions of the FX-7000G can be calculated with up to 13 digits, using arithmetic and algebraic computations as follows: It can compute square roots, basic math, reciprocals, exponential functions, factorials, logarithms and trig functions. It also offers special functions to include hyperbolic, statistical, binary, octal, hexadecimal, sexagesimal conversions, and graph plotting.
The FX-7000G is programmable with 422 bytes of storage memory. The user can save a program they create or are creating in one of ten programming slots. Language used for programming is tokenized, which uses characters and symbols instead of lines of code, this minimizes the use of memory. The calculator has 26 numeric memories standard, but up to 78 can be created by the user by reducing the number of bytes available for programs.
It has a built-in graphing feature that can display either installed graphs or user-defined graphs. The user can also rewrite any of the programmed graphs. Graphs can also be created in the following styles, bar graphs, line graphs, normal distribution curves, and regression lines.
The display uses an LCD Dot Matrix design, which is not capable of a color or grey-scale display. When in character mode it can display up to sixteen characters on each of the eight display lines.
It has a black casing around the unit and a metal panel on the rear. The LCD display is protected by a large plastic screen. The keys are colored in orange, green, blue, red, and black, with each one labeled for its function.
It is powered by a 9.0-volt DC lithium battery supply using three CR2032 type cells, and only uses batteries for its power, with and average battery life of 120 hours of use.
The calculator has two keyboards and a display screen on the face. There is a slider switch for on/off half-way up the left side of the unit. The lower keyboard is the traditional Casio layout with an EXE key for executions, and an Ans key that could be used for showing the last answer. The upper keyboard has the main function keys. The Shift and Alpha keys are used to access many functions of the other keys.
The main screen displays the system mode, calculation mode, angle and rounding mode. Modes are changed by pressing the mode button, or shift then mode. Depending on the function wanted as shown on the writing below the screen.