Electronic computing apparatus employing basic language

Abstract

An adaptable programmable calculator is provided by employing a modular read-write and read-only memory unit capable of being expanded to provide the calculator with additional program and data storage functions oriented towards the environment of the user, a central processing unit capable of performing both serial binary and parallel binary-coded-decimal arithmetic, and an input-output control unit capable of bidirectionally transferring information between the memory or central processing units and a number of input and output units. The memory, central processor, and input-output control units are controlled by a microprocessor included in the central processing unit. Also the calculator may be operated manually by the user from an alphanumeric keyboard input unit or automatically by a program stored within the memory unit to perform calculations and provide an output indication of the results thereof. It may also be employed to load programs into the memory unit from the keyboard input unit. Also, the computer language allows the user to enter a line comprising an alphanumeric statement into the calculator from the keyboard input unit while visually observing an alphanumeric display of that line to check for errors therein, permitting the user to cause the entered lines to be immediately executed by the calculator or stored as part of a program within the memory unit, and permitting the user to subsequently recall the executed or stored line so that it may be reinspected, reevaluated, and, if necessary, edited and executed or re-executed, or restored in edited form. The calculator employs a compiler for converting each statement entered into the calculator in BASIC language into an internal stored format. It also employs an uncompiler for regenerating in the BASIC language statement any entered line converted to the internal stored format. The compiler and uncompiler operate on a line-by-line basis.