As for the solaris it is probably only UNIX where ignoring the ISO C rule that anything ending with "_t" is reserved for implementation will bite you hard as so

As for the solaris it is probably only UNIX where ignoring the ISO C rule that anything ending with "_t" is reserved for implementation will bite you hard as solaris' libc headers are probably the main reason for that and typedef stuff like lock_t. As for the rest doing cycle exact emulation of 50 year old system is and probably always will be doable and from some PoV trivial: you can just simulate the hardware logic of the original implementation on RTL or even gate level and it still will be faster than realtime. [Edit: "reserved for implementation" was missing from the first paragraph]