Using specs for Lisp 1.5 outlined in [1], [2] would make for an inexpensive lisp language prom.
Or perhaps more pratical if used with [3] and gpt3.
[1] http://www.paulgraham.com/rootsoflisp.html
[2] https://hackaday.com/2023/01/20/help-needed-on-thumb-image-rp2040-dma-hack-makes-another-cpu-core/
[3] https://docs.arduino.cc/hardware/nicla-voice