A basic interactive system now requires less than 4KiB, and a full featured system is below 5KiB. By now, most of the "outer interpreter" and "compiler" words have been converted to a mix of Forth VM code and assembly, and further size reduction would require a different design of the Forth VM (e.g. DTC using the return stack as the data stack, or even ITC). Maybe I'll try that one day, but not in the scope of this project.

In other words, the implementation of the STM8EF core should now be considered "stable". The latest push to the develop branch on GitHub was no changes at all, but a "retab" that was a bit overdue (no more tab chars please, thank you).

The headroom I gained will now be used carefully for adding features, and I'm now working on adding communication words, e.g. for concurrent serial communication in foreground and background.