[commodorejohn]

So I'm in the middle of extending one of my bits of hobby-project software (a simulator for a homebrew CPU project) to support asynchronous I/O, in order to be able to run the simulation in "real time." This is a mild adventure for me as it's the first time I've ever had occasion to dig down into the *nix kernel I/O functions as opposed to just rolling with stdio, but overall, nothing too crazy.

However, one of my random just-for-kicks goals is to be able to host it on one of my vintage workstations, and I'm running up against that age-old problem with documentation in Our Modern Age: it's trivial to find out what's supported now, on modern *nixen, but is there any good way to find out about the history of various kernel features on the interwebs?

Like, the documentation all says that the aio library is POSIX, but was it created for the POSIX standard, or something codified out of older SysV or BSD functionality? Will I find it on, say, SunOS 4, etc.? I suppose I can just boot my SparcStation and check the man pages, but it seems typically silly of the modern Internet that I'd have to bother doing that.