[captbill]

Oberon is mind boggling, in all respects. You can download the emulator (<5mb total). It is SDL2 based so runs like a stand alone app, no VirtualBox or QEMU needed. Then you can get and compile Lola-2, the Verilog pre-processor compiler from Prof. Wirth. Now you can literally compile the RISC5 processor "chip" itself which runs on the FPGA!! Just use the output .v files from Lola-2 and compile with the Xilinx toolchain. Next you can compile the "Oberon OS" quite simply by hand in a few minutes. With a compile script the complete OS compiles in 10 seconds.

Then why not finish off with PICL, the language/compiler for the PIC16. Includes the uploader. All in <700 lines of Oberon code. The best part is the amazing tutorials/documentation. Some amazing finds at Prof Wirths personal site. https://www.inf.ethz.ch/personal/wirth/

This has to be the most jam packed tutorial you could ever hope for: https://www.inf.ethz.ch/personal/wirth/PICL/PIC.pdf