Mac OS 7 “Virtual Memory” was just the swap file. Fundamentally classic Mac OS had a flat memory layout with special hooks defined that did not allow for virtual memory as more commonly defined. Multiprocessing came in asymmetric and symmetric forms but really wasn’t terribly useful until 8.5/8.6 and later but by that time Mac OS X was about to show up which solved all these issues.

Yes I should have been more precise about the virtual memory. There was something like it that could swap to disk (in os 8 i think). Anyone remember RAMDoubler? It wasn't anything like the UNIX VM that came with MacOSX.