The UXN project might also be fun, the virtual machine is fairly simple to implement and there are a lot of interesting programs written for it. https://wiki

The UXN project might also be fun, the virtual machine is fairly simple to implement and there are a lot of interesting programs written for it. https://wiki.xxiivv.com/site/uxn.html There is also the LC3 virtual virtual machine, with a fairly great guide on creating it. https://justinmeiners.github.io/lc3-vm/