Inventors:
Bradley W. Miller - Loveland CO
Franklin T. Hickenlooper - Loveland CO
David C. Uhlrich - Loveland CO
Marl D. Godfrey - Loveland CO
Douglas M. Clifford - Loveland CO
Rex L. James - Loveland CO
Robert E. Watson - Loveland CO
John C. Keith - Loveland CO
Alan C. Mortensen - Loveland CO
Assignee:
Hewlett-Packard Company - Palo Alto CA
International Classification:
G06F 906
Abstract:
An adaptable 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, an LSI NMOS central processing unit, and an LSI NMOS peripheral interface adaptor capable of bidirectionally transferring information between the read-write memory and central processing unit and a number of input/output units. The modular read-write memory includes a movable boundary between a program storage section thereof and a data storage section thereof to permit the user to adjust the size of those sections of the read-write memory in accordance with his present problem solving requirements. The input/output units include a keyboard input unit with a plurality of alphanumeric keys, a magnetic tape cassette reading and recording unit capable of bidirectionally transferring programs and data between a magnetic tape and the calculator, a seven-segment gas discharge display for displaying data entered into the calculator, the results of computations, and selected alphanumeric messages, and a 16-column alphanumeric thermal printer for printing results of computations, program listings, messages generated by the user and the calculator itself, and error conditions encountered during use of the calculator. All of these input/output units are included within the calculator itself.