Real-Time Recognition of Handprinted Text

Documentation of an IBM/360 assembly language program for online graphical-input character recognition using the RAND Tablet. The program is written as a reentrant process and requires about 3700 32-bit words of storage. The user must provide his own programs for communicating with the Tablet and CRT display of symbols. The program recognizes handprinted letters, numbers, punctuation marks, and geometric figures; it separates characters written in quick succession and in close proximity. As the user writes on the Tablet, the program tests the positional data for directions, corners, position, maxima and minima, and relationship to previous strokes. When a set of strokes is recognized as a character, its stylus track is replaced on the CRT by a neat standard version. About ninety percent of the characters are recognized correctly by the program; correction by the user is easy. The Memorandum consists mainly of the program printout, with extensive internal commentary. Directions are appended for using the program with the standard IBM OS/360 operating system and 2250 CRT display unit. (See also RM-5016-ARPA.)