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> A USB that could plug in correctly both ways would have required double the wires and circuits, which would have then doubled the cost. why couldn't they hav

by zzzeek 7y ago

> A USB that could plug in correctly both ways would have required double the wires and circuits, which would have then doubled the cost. why couldn't they have used a notch / tab like other connectors do? not durable enough?

kuon 7y ago
I'm pretty sure some Apple USB had a notch. But I think it wasn't to help to plug it in, I think it was to ensure it was directly plugged into the computer without using a cable extension. But I don't remember well, it's only speculations.
- lonelappde 7y ago
  You got it backwards. The notch was for compatibility with the extension cable, which had a lug because USB extension cables are not allowed by the spec (too much distance for the signal), so the lug prevented you from using the extension cable with a device that might fail.
  - lilyball 7y ago
    Also this way you can't plug two extension cables into each other, because the cable didn't have the notch, only the lug.
  - kuon 7y ago
    You are right, it was on the extension cable!
cogman10 7y ago
My guess is that it's harder to manufacture. Probably not a good reason though as those harder to manufacture things already existed with Serial and Parallel ports.