Abstract: A programmable calculator employs modular read-write and read-only memories separately expandable to provide additional program and data storage functions within the calculator oriented toward the environment of the user and two sixteen bit LSI NMOS central processing units. One of the central processing units (LPU) is employed to perform language syntaxing, arithmetic, and general supervision of program execution. The second central processing unit (PPU) is employed for managing input/output operations. Communication between the two central processing units is accomplished by an arrangement through which the two central processing units share a common portion of memory. The calculator also includes a keyboard having a full complement of alphanumeric keys for entering programs and data into the calculator and for otherwise allowing the user to control operation of the calculator.

Abstract: An adaptable calculator is provided by employing five MOS/LSI circuits interconnected by a multiple line bus system. They include (1) a read-only memory circuit group; (2) a control and timing circuit; (3) an arithmetic and register circuit; (4) a data storage circuit; and (5) an input/output (I/O) circuit. Input and output units include a keyboard input unit and an 18-column output printer unit for printing intermediate results of calculations, entered data, arithmetic operators, and diagnostic notes. The keyboard input unit includes a PERCENT key that may be employed in combination with any of four arithmetic operator keys. The calculator may be operated manually by the user from the keyboard input unit or automatically by a program written in user-level language and stored in a plug-in read-only memory unit (ROM), a plug-in programmable read-only memory unit (PROM) or a read/write memory unit associated with a plug-in magnetic card reading and recording unit.

Abstract: A programmable calculator employs modular read-write and read-only memories separately expandable to provide additional program and data storage functions within the calculator oriented toward the environment of the user and two sixteen bit LSI NMOS central processing units. One of the central processing units (LPU) is employed to perform language syntaxing, arithmetic, and general supervision of program execution. The second central processing unit (PPU) is employed for managing input/output operations. Communication between the two central processing units is accomplished by an arrangement through which the two central processing units share a common portion of memory. The calculator also includes a keyboard having a full complement of alphanumeric keys for entering programs and data into the calculator and for otherwise allowing the user to control operation of the calculator.

Abstract: An adaptable calculator is provided by employing five MOS/LSI circuits interconnected by a multiple line bus system. They include (1) a read-only memory circuit group; (2) a control and timing circuit; (3) an arithmetic and register circuit; (4) a data storage circuit; and (5) an input/output (I/O) circuit.Input and output units include a keyboard input unit and an 18-column output printer unit. An optional LED display unit may be plugged into the calculator mainframe. The keyboard input unit includes an AUTO DECIMAL POINT key for selecting an automatic decimal point mode of calculator operation in which the calculator automatically places the decimal point at a specified location in all entered data. Thus, the operator need not manually enter the decimal point in entered data. The calculator may be operated manually by the user from the keyboard input unit or automatically by a program stored in the calculator memory.

Abstract: An adaptable calculator is provided by employing five MOS/LSI circuits interconnected by a multiple line bus system.