[TUHS] Device special files

[Random832]

On Tue, Feb 6, 2018, at 10:56, ron minnich wrote:
> these were in by the time I can along but I was wondering when they got it.
> 
> They've also always felt a bit like a thing that did not fit to me. I'm
> pretty sure I was not alone, given that the Unix authors worked out a way
> to get rid of them in later efforts. I know what came after, in Plan 9;
> what came before, in Unix, that led to special files?

V3 and earlier still *called* them special files, but it seems they were essentially just magic inode numbers (there was no physical file on disk, just any directory entry with the given inode would be the special file).

http://minnie.tuhs.org/cgi-bin/utree.pl?file=V3/man/man5/fs.5