Abstract: A computer has an operating system with a graphical user interface. This computer also has a key manager for graphically associating objects, such as data or application programs, with keystrokes, such as Fn-Fx key combinations, where Fn is a special shift key and Fx is a numbered function key. A key group or folder contains icons which represent objects. This key group can be built or modified by the user by copying an icon contained in another program group or folder via a drag and drop or similar operation. The key manager interrogates the operating system for the contents of the key group, and receives a key array. The key array contains objects associated with keystrokes. The key manager then monitors the operating system for any keystrokes received from the user. Upon receipt of a keystroke, the key manager determines whether the keystroke is in the key group.

Abstract: Optical transceiver (22) for calculator-to-calculator or calculator-to-module communication. The transceiver (22) includes an IR transmitter (24) and IR receiver (26) designed for use in the low power, low cost environment of calculators and portable computing devices. The transceiver may be adapted to communicate with the CPU (central processing unit (14) of a calculator (90) directly or with that of a portable computing device via its serial port (43). Devices in which the optical transceiver may be incorporated include calculators, plugless modules, and books containing plugless modules. Data such as mathematical formulas within the book may be stored in the associated module and transferred instantaneously and accurately to an adjacent calculator upon request by the calculator.

Abstract: A portable computer unit contained within a substantially planar housing a minimal thickness designed for transport in a ring-type notebook binder. Specifically, the housing includes an upper section having a plurality of openings which are sized to receive the binder rings. Once the binder rings are inserted within the openings of the housing, the entire computer unit may be easily transported within the binder. Transport in this manner also obscures the computer from view, diminishing the possibility of theft.