It doesn't really matter :0) but please don't be offended I'm just replying for clarity of my point.

I didn't say tape player i said Walkman which is also to say the first personal compact disc player, which Sony did invent.

The PlayStation is an invention how can it not be classed as such? It was a completely unique device when released and revolutionised home entertainment as the CD used was much cheaper to produce over cartridge based alternatives, the word Invention it is also a process the PlayStation went through this during its creation it was invented by engineers, so in my old head I would class it as such :0)

As for the CD well yes and no, the CD as we know it was based on patents from James Russell, his patents were about storing data on a transparent film which was back lit to be read, the laser based CD reading technology was a joint venture using those patents as a starting point, Sony and Philips invented this version of the storage medium well...after a bit of red tape corporate bs.