[pjmlp]

Indeed, IBM PC certainly didn't had one and I had to wait until MS-DOS 5 to use one, that wasn't a game.

As someone that started on Timex 2068, I can certainly say that no one referred to CP/M, MSX, Atari, Amiga or Mac as being PC.

The word PC was definitely known as being IBM PC with either IBM PC-DOS or MS-DOS.