PROGRAMMABLE CALCULATOR

摘要

IMPROVED PROGRAMMABLE CALCULATOR An adaptable programmable calculator is provided by employing a modular read-write and read-only memory unit, a central processing unit, 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 processing, and inputoutput control units are controlled by a microprocessor. A keyboard input unit with a plurality of sections capable of being defined by plug-in read-only memory modules and stored programs added by the user, a magnetic card reading and recording unit, a solid state output display unit, and an output printer unit are included among the input and output units. The calculator employs a high level algebraic keyboard language permitting the user to enter a line of one or more alphameric statements into the calculator from the keyboard input unit while visually observing an alphameric display of the line being entered to check for errors therein, permitting the user to cause the entered lines to be immediately executed by the calculator and/or stored as part of a program within the memory unit, and permitting the user to subsequently recall the executed and/or stored line, so that it may be reinspected, re-evaluated and if necessary, edited and executed or reexecuted. The calculator also employs a compiler for converting each line entered into the calculator in the high level keyboard language into a post-fix polish code and an uncompiler for regenerating in the high-level keyboard language any entered line converted to the post-fix polish code. Both the compiler and the uncompiler operate on a line-by-line basis.