Abstract: In a data decompression system of the type having a self-compiling dictionary for building or replicating codes used for decoding incoming code values, there is provided a decoded string dictionary or memory for storing plural characters representing decoded strings. The decoded strings may be stored in a modified dictionary replacing string codes or stored in a separate variable length memory as blocks of characters having predetermined length and accessed using a finder memory. If the decoded string becomes too long to be stored in a fixed length memory, a conventional decoder dictionary may be used to reduce the size of the strings stored for direct access and read out to a recovered data stream.

Abstract: The present invention provides a novel method and system for obtaining maximum system speed performance for compressing coded data characters in a serial data stream by replacing strings of data with code values stored in a dictionary when strings are first observed as unique strings in the data stream. A novel pointer address is generated to represent new strings to be searched in the dictionary. The novel pointer address comprises a string code portion representative of the last matched string found in the dictionary and appended thereto an extension character code portion representative of the next character taken from the input data stream. The dictionary is constructed large enough to provide a unique memory location for every possible pointer address. The unique pointer address, representative of a string of data in the input data stream, is employed as an address pointer to access the memory.