[Hoff]

For those old grey-hairs around and reading that remember RSX-11M/M+, there was a tool known as TKB.

The task builder.

TKB allowed (much) larger applications to run in the address space of a 16-bit DEC PDP-11, using what were called overlays, and overlay trees.

With overlays, the application call tree within an application was analyzed and implemented to allow various sections of code within a tree of subroutine calls to be paged out to backing storage.

If the underlying "processor" is fast enough and if you have enough swap space available, then you can stuff a whole lot of code into a 16-bit address space. Just not all loaded in physical memory at once.

And debugging it... Shudder...