METHOD AND APPARATUS FOR ALLOCATING MEMORY TO REDUCE CONVENTIONAL MEMORY REQUIREMENTS

The present invention provides an environment for DOS executable programs or "modules" that are constructed so that they can cooperate with other similarly constructed programs in sharing memory used by portions of their code or data. This reduces the overall requirements of conventional memory (102). The modules include transient code and data (403), that may be swapped out of conventional memory, and global code and data (402) that is not swappable and stays resident in conventional memory. The present invention reduces conventional memory requirements by allowing modules to share a single block of conventional memory for transient code and data. Instead of swapping transient blocks of modules to and from disk storage (204), the transient blocks are swapped between conventional memory and extended (111) or expanded memory (406). This significantly reduces transfer time compared to overlay schemes, improving performance.