If you were lucky enough to have an Amiga with a CPU that did have an MMU, you could use a piece of freely-downloadable software (called GigaMem) to implement

If you were lucky enough to have an Amiga with a CPU that did have an MMU, you could use a piece of freely-downloadable software (called GigaMem) to implement paged virtual memory - albeit still with a single address space. One of those few operating systems that could have virtual memory implemented outside the OS kernel.