"File types"

Hi, When did the notion of "file types" creep into computing? Hmmm... poorly phrased. How about: "When did the notion of file *associations* (?) creep in?". I don't seem to recall having any problem typing: qedx myfile.mp3 or even: qedx a.out (et al.) I know Apple had "file creator" attributes that were semi-hidden (i.e. not part of the file *name*). Is the concept of a "file extension" an outgrowth of the 8.3 naming scheme? Or, does it have its roots further back? Is there any rationale for this sort of an implementation? Or, just one of convenience (i.e. "there was no other space in the dirent to store this stuff so we came up with the idea of just bastardizing the name space to accommodate it"). Since I am not fond of Hungarian notation and consider this just another variant (precursor) thereof, I wonder why it persists? Has Apple abandoned the "hidden" file creator attributes of earlier MacOS in newer OS's (e.g., OS X)? Or, have they bowed to user pressure and implemented a "me-too" scheme?