A method of generating an output vector to identify a character-of-interest using a sparse distributed memory (SDM) module. The method includes obtaining a feature vector having a vector address. The feature vector is based on a character-of-interest in an acquired image. The method also includes identifying activated locations from hard locations by determining relative distances between the vector address and the stored vector location addresses. Stored content counters of the activated locations include first and second stored sub-sets of counters. The method also includes combining the counters of the first stored sub-sets of the activated locations using a first summation thread to provide a first combined sub-set of values. The method also includes combining the counters of the second stored sub-sets of the activated locations using a second summation thread to provide a second combined sub-set of values. The first and second summation threads are run in parallel.