The history in the video doesn't ring quite right. The heritage of the PS/2 keyboard also relate to mainframe terminals (3270 and maybe 5250) which predate the

The history in the video doesn't ring quite right. The heritage of the PS/2 keyboard also relate to mainframe terminals (3270 and maybe 5250) which predate the IBM PC and to the original IBM/AT keyboard which predates the PS/2. Presumably some of those have electric typewriter heritage as well. I also think some of those older keyboards were nicer than the PS/2 IMNHO.