Texas Instruments Corporation

David Caldwell

Arthur C Hunter

Linda J Ferrio

Samir W Rizk

Mahendra P Agrawal

The equation operating system is an improved data and command entry format together with a compatible operation system for use with electronic data processing apparatuses, most particularly with scientific calculators which provide an alphanumeric display of entered equations. This invention provides a different set of commands and displayed characters for performing exponentiation. An up arrow together with a down arrow serve to define the expression of the exponent. The numeric data stored in a numeric display register upon implementation of the exponentiation is raised to the power of the expression between the up arrow and the down arrow. This invention also includes an integral power exponentiation command which enables easy entry of single digit positive integral exponents, thereby eliminating the need for a completing command.

Electronic data processing apparatus with equation operating system

The equation operating system is an improved data and command entry format together with a compatible operation system for use with electronic data processing apparatuses, most particularly with scientific calculators which provide an alphanumeric display of entered equations. This invention also includes a unary operation implementation technique, whereby the operand may be entered either before or after the unary operation.

A data processing apparatus employs a single key stroke for defining a complex number entry and for designating a particular complex number calculation mode. Entry of a complex number follows the following format: entry of the first part of the complex number, entry of a complex number mode designation command, and entry of the second part of the complex number. Entry of the complex number mode designation command designates the numeric data to be assigned the first part and the second part of a complex number and also causes the data processing apparatus to enter a corresponding complex number computation mode. Thereafter, upon entry of at least some of the normal operational commands of the data processing apparatus, these operational commands are performed upon the previously entered complex numbers in accordance with the mathematical laws of complex number arithmetic. The data processing apparatus preferably generates an indication of when a complex number computation mode has been set. Display of the two parts of a complex number is facilitated by an exchange operational command which exchanges the first and second parts of the complex number so that the other part of the complex number may be displayed. In a further preferred embodiment, complex numbers may be stored and recalled from pairs of user accessible memories in a manner similar to the normal operations on real numbers.

Method of entering and performing operations on complex numbers on

The equation operating system is an improved data and command entry format together with a compatible operation system for use with electronic data processing apparatuses, most particularly with scientific calculators which provide an alphanumeric display of entered equations. This invention provides an implied multiplication having differing hierarchical ranks when one of a member of a predetermined prefix set entry is followed by one of two differing suffix set entries. Each of these implied multiplications have a differing hierarchical rank than that of explicit multiplication.

A data processing apparatus having a plurality of preprogrammed functional operations and at least one user accessible memory includes a generalized input sequence for combining functional operations with data storage in one of the user accessible memories. In the case where a number of user accessible memories is provided, memory entry is enabled by a store input followed by an input designating the memory while a memory recall operation is enabled by a recall input followed by a memory designation input. The algebraic memory operation and entry sequence requires entry of the store input, the desired operation input and the memory designation input. If a unary operation is selected, the selected operation is performed on the data stored in the output indicator memory or alternately on the data stored in the designated memory and the result is stored in the designated memory. If a binary operation is selected, the selected operation is performed using the data stored in the designated memory as the first operand and the data stored in the output indicator memory as the second operand, and the result is stored in the designated memory. With modifications this entry sequence can also be used to perform combined operations and memory entry for an apparatus having only one user accessible memory.

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Lubbock, TX, United States of America

David Caldwell