Abstract: This disclosure relates to a system embodied in a data processor for source to source code translation of programs, and to the method by which such translation is accomplished. The particular system disclosed is one for translation of programs in the RPG source language to the COBOL source language. The method involves the sequence of four passes through the RPG source code during which, each record is read. On the first pass, the RPG syntax is checked for error and required tables are created. The second pass reads intermediate files and generates COBOL data declarations and also builds tables and switches for later passes. The emitted code is stored on intermediate disk files. During the third pass, executable instructions in COBOL code for the first part of COBOL procedures are generated from a first half of the RPG source and the code thus generated is stored in the COBOL source language file.