Manual data input device for a numerical control apparatus

摘要

A data input device equipped with a keyboard including a plurality of keys at least some of which are assigned both a letter of the alphabet and a numerical value, which keys are operated to generate signals representing data that comprises a letter of the alphabet and numerical values immediately following the letter. The initial operation of one of the keys produces the data indicated by the letter of the alphabet assigned to that key, and subsequent operation of the keys produces the data indicated by the numerical values assigned to the keys that have been operated.