While reading about other things on Hackaday, I found this interesting article on the history of Zork. How it was a tour de force of programming techniques to cram a mainframe computer onto a microcomputer using virtual machine techniques.
20191110/https://hackaday.com/2019/05/22/zork-and-the-z-machine-bringing-the-mainframe-to-8-bit-home-computers/