I find these kinds of very basic intro articles frustrating. They till the same ground over and over: a tiny instruction set implemented with a switch statement. None of the more difficult issues are addressed: exception handling, linking to libraries or other programs written for the same VM, portability of programs across architectures, accessing the OS for services like file I/O, time, etc.-- All the things that make a toy not a toy.
Every CS student in the world has written a toy VM just like this one.
Every CS student in the world has written a toy VM just like this one.