Abstract: A portable electronic computer for conducting fraction calculations has a display including a first multiple-digit display area for displaying the numerator of a fraction, and a second multiple-digit display area for displaying the denominator of the fraction. The numbers of digits of the numerator and denominator of a fraction to be displayed are obtained. The number of digits of the numerator is compared with the number of digits of the denominator. The difference between the number of digits of the numerator and the number of digits of the denominator is calculated. When the number of digits of the numerator is smaller than the number of digits of the denominator, the numerator is displayed on the first display area with its position shifted to an upper digit place according to the difference.

Abstract: A computer or calculator which can use a retrieved data in any position of an expression. The computer has a calculation mode and a data retrieval mode, and comprises an X register for an input data, and a Y register for an operand. In the computer, the contents of the X register is loaded into the Y register when a predetermined key operation is conducted in the calculation mode, and then the mode of the computer is set to the data retrieval mode. A retrieved data is loaded into the X register, and the mode of the computer returns to the calculation mode.

Abstract: An improved electronic computer which can produce a quotient/remainder calculation. The computer has first and second memories for storing respectively a dividend and a divisor which are input for execution of division. A quotient/remainder calculation is carried out using the dividend and divisor stored respectively in the first and second memories. The computer further includes third and fourth memories for storing respectively a quotient and a remainder which are obtained in the division calculation. A detector is provided for detecting which of the contents of the third memory or the contents of the fourth memory are displayed. The contents of the third memory or the contents of the fourth memory which have not been detected as being displayed are displayed in response to a predetermined input operation.

Abstract: A calculator which can display not only numerical digits but also arithmetic operational signs and functional symbols. A display portion of the calculator has a numerical value display portion on its lower side and an expression display portion on its upper side, wherein a cursor appears only in the expression display portion. Any digit inputted from numerical keys is first displayed at the numerical value display portion, and such a digit is inputted into the expression display portion when a key for giving instructions to perform an operation is depressed. A CPU clears all of input numerical digits displayed at the numerical value display portion and shifts a cursor back to an end of a mathematical expression displayed at the expression display portion when a cursor-left-shift is operated. When a cursor-right-shift key is operated, the CPU deletes a digit located at the lowest position of the numerical value display portion.

Abstract: A multi-functional electronic desk calculator has numeral value keys for inputting a numeral value and a decimal point key for inputting a decimal point. The calculator also has a device for detecting depression of the numeral value keys to produce a first signal representative of being in a numeral value inputting mode, a device for detecting depression of the decimal point key to produce a second signal representative of input of the decimal point, a predetermined single key, and a device for operating the predetermined single key as a key used for inputting hexagesimal number when the first signal is produced and the second signal is not produced, and for operating the predetermined single key as a conversion key for performing conversion from decimal number to hexagesimal number when the first signal is not produced or when the second signal is produced.

Abstract: An electronic calculator having a graph displaying function is adapted so that when a display range along only one coordinate axis is specified, an optimum display range for the other coordinate axis is automatically determined for displaying a graph within the display ranges. The remainder of the graph other than the portion thereof presented on the graph display is shown from portion to portion by scrolling along the trace of the graph in accordance with the result of the calculation being performed to determine the remainder. All of the data in a random access memory (RAM) can be transferred to an external device for the protection of the data when the device is connected to the calculator.

Abstract: An electronic calculator carries out input of data, such as numeric values, stores data therein, and performs operations and processing of the input data according to the operation of necessary function keys. Further, inputted matrix data is stored in relation to one code so that when operating the matrix data, the code is utilized for inputting an operational expression, whereby the procedure for inputting such data for operation can be considerably simplified. If it is desired to preserve input data, the data can be protected by preventing rewriting or redefinition thereof. Also, data processing is enabled which excludes any data abnormally different from other data, thereby enhancing the reliability of the results of the data processing.

Abstract: An input device for inputting a first word represented in a first language, the input device being adapted for an electronic translator for obtaining a second word represented in a second language, equivalent to the first word, in response to the input of the first word, comprises a first specifying key for specifying one of alphabets to define a first alphabet, a second specifying key for specifying one of the alphabets to define a second alphabet, an input device for controlling the first and the second specifying keys to input said first and second alphabets into the electronic translator, a memory for memorizing a plurality of full words, an access circuit provided for addressing the memory words starting with the first and second alphabets, and a display responsive to the access circuit for displaying the words.