Text comparator with counters for indicating positions of correctly decoding text elements within an ordered sequence of text elements

摘要

A text comparator which includes a decoded data memory (13) which contains a plurality of shift registers (SR2.0.-SR7F), one shift register for each one of the plurality of different symbols forming the data base stored within the mass storage device (11). The decoded signal is applied to the input lead of the shift register associated with that character, and a clock signal applied to each shift register of the decoded data memory. In this manner, the decoded data memory will provide signals on the output leads of each shift register indicative of the most recently received character, as well as each of the preceding K characters received from the mass storage device and decoded, where K is the number of bits contained in each shift register of the decoded data memory. The output lead of the shift registers are connected to the input leads of a variety of logical gates, such as AND gates and OR gates, in order to provide an output signal indicating when the desired textual phrase has been located on the disk. In addition, word counters, paragraph counters, and other devices are employed as desired to provide special text comparison functions.