There's also the possibility that they are something else entirely.
Our own real-life computer tech has gone from vacuum tubes to paper punch cards to magnetic reels to optical discs to you name it. And that's only in decades.
TOS centuries from now? Those TOS squares? They may well be something that doesn't have any modern-day equivalent, a kind of computer tech that seems familiar but may be unlike anything we have today.
I'm just saying. Could be.