Now, the conventional wisdom is that the OS was "System Software" as its official name from release 5 through 7.5.5; but that the "Mac OS" splash screen came along in 7.5.1. Starting with 7.6, it was purely "Mac OS".
But in my recent playing around on my two 7.6.1-running machines, I have noticed that in Extensions Manager, when you view by package, there is a "System Software 7.6" package, and a "Mac OS 7.6.1 Update" package. Obviously, someone didn't get the "It's now Mac OS" memo in time for 7.6's release.
Also, funnily, the "Apple Built-In Ethernet" and "Apple Ethernet NB" extensions are of the misspelled package "System Sofware 7.6", missing the 't'.
But in my recent playing around on my two 7.6.1-running machines, I have noticed that in Extensions Manager, when you view by package, there is a "System Software 7.6" package, and a "Mac OS 7.6.1 Update" package. Obviously, someone didn't get the "It's now Mac OS" memo in time for 7.6's release.
Also, funnily, the "Apple Built-In Ethernet" and "Apple Ethernet NB" extensions are of the misspelled package "System Sofware 7.6", missing the 't'.