A software technique that compresses the contents of memory, thereby doubling (more or less) its available capacity. Used in the 1990s when memory was expensive, MagnaRAM was a popular RAM doubler that was also part of Quarterdeck's extended memory manager (see QEMM
). MagnaRAM inserted itself into the virtual memory system, compressing the contents of memory headed for the hard disk in its own buffer. When full, the buffer contents were copied to disk.