Thanks for the explanation. Very nice project. I guess self-modifying code does not work with this technique, does it? (I don't know much about DOS games and how common self-modifying code was on PCs).

Concerning access to video memory: I saw that you treat them "manually" in some cases. I am wondering whether you could avoid that by using virtual memory. You could mark the pages as invalid and when an instruction tries to access them, you catch it and replace the memory[...] access instruction by a call to memoryVideoGet. The JIT-Compiler of the Amiga emulator uses a similar technique for indirect accesses to hardware registers.