A system for preprocessing computer programs before downloading them into terminals includes a packager (303) which processes certain information contained in compiled but unlinked programs (307). The packager (303) partially resolves undefined symbols and relocations based on knowledge of a dispatch table (310) in the destination terminal (302) and other information known prior to downloading process. Packager (303) determines sizes of separate code, data dispatch table and temporary symbol areas, incorporates this size information into a header (309d), and transmits a data stream including the header and the aforementioned areas, including partially resolved symbols, to one or more terminals such as home communication terminals (HCTs) in a cable television network. Each receiving terminal (302) extracts the size information and allocates only as much memory as is needed to store each of the separate areas, thus avoiding the need for temporary holding buffer. Receiving terminal thereafter relocates remaining executable instructions to prepare the computer program for execution.