its not just Word, save means save. Unless you protect the original you are saving on top of it. The "save" command works like this universally (even on your c1978 TRS)
BTW- The iphone is a computer.
TRS-80 didn't have menus.
And the iPhone is a computer, but its user interface is most assuredly different than any other computer. It is more like an appliance and less like a computer. As it should be. If you want windows-style menus, go use a WM device.