"Cellular Automata Machines: A New Environment for Modeling" is one of my favorite books of all time! It shows lots of peculiarly indented Forth code.

https://donhopkins.com/home/cam-book.pdf

CAM6 Simulator Demo:

https://www.youtube.com/watch?v=LyLMHxRNuck

Forth source code for CAM-6 hardware:

https://donhopkins.com/home/code/tomt-cam-forth-scr.txt

https://donhopkins.com/home/code/tomt-users-forth-scr.txt