I think the open apple was introduced with the ADB keyboards, which worked both with Macintosh and IIGS computers. The open apple was for Apple II computers and

I think the open apple was introduced with the ADB keyboards, which worked both with Macintosh and IIGS computers. The open apple was for Apple II computers and applications; the knotty loop was for the Mac and its applications. The original Mac keyboards (serial, with the telephone handset connector) did not have the open apple symbol. I don't recall any Mac applications making reference to the open Apple key, it was always "Command Key." From the Mac side, "open apple" was a colloquialism.