the decision was made to go with a design that, in theory, would give users a 50/50 chance of plugging it in correctly
How could it be less than that? If it was triangular?
Ugh those circular power cables that from the 90s that only had pins in one half…
The PS2 (and AT) connectors keyboards and mice were largely using before USB were round…
Arguably still better though because you could just rotate the plug until it went in instead of flipping it back and forth 5 times to get it to go in. And they also had more reliable indication for orientation.
you could just rotate the plug until it went in
That was a good way to twist and bend up all the pins. Don’t you remember how fragile they were?
You know all the jokes about getting usb’s orientation right on first try, failing to push it in and trying the other way? Yeah, it was already worse than 50/50.
Honestly that connector always felt like shit. A tiny, easily identifiable mark/notch/whatever on both plug and port would have made it a lot better, even if it was still non-reversible.
That’s such a simple reason and makes so much sense.
Making USB reversible to begin with would have necessitated twice as many wires and twice as many circuits, and would have doubled the cost. Bhatt says his team was aware at the time of the frustration that a rectangular design could have, versus a round connector. But in an effort to keep it as cheap as possible, the decision was made to go with a design that, in theory, would give users a 50/50 chance of plugging it in correctly (you can up the odds by looking at the inside first, or identifying the logo).
I have my doubts. I think that a jack-like (circular) connector wouldn’t require twice as many wires and circuits. Actually absolutely the same amount. The connector itself would require more metal to make.
And the chance of correctly plugging that in would be like 99/100 (1/100 for breaking it).
I was there when we had lots of “round” connectors like Din connectors but also lots of proprietary ones.
That was way worse, trying for the eleventh time to put it in correctly without looking as it’s under/on the backside in a jungle of other cables, and not damaging any of the fragile 7 pins… gargl.
The trick with DIN connectors was to try to insert them gently while rotating them. Once you got the notch lined up they would very clearly drop into the socket at which point you could apply more pressure to fully seat them. It was only a problem if you were jamming them in full force while rotating because you could exert enough pressure to force it into the socket even with the key notch misaligned crushing the pins. I never once had a problem inserting a DIN connector, something I absolutely can’t say about USB-A.
TL:DR; It was cheaper and they figured if it didn’t work you could flip it over and try again. So it’s mildly inconvenient to save a few cents on manufacturing each connector and to limited the number is conductors to 4, something it turns out was a bad idea anyway because newer USB standards use more than 4 conductors.
That is one way to deal with the problem, but it comes with its own tradeoffs. In particular that reversible type-a is incredibly fragile due to how thin the plastic supporting the pins needs to be to fit within the housing. They could make the plug bigger of course, but now you’re adding more cost and decreasing the areas the plug can potentially be used in due to its increased size. Conductor routing also becomes more problematic as you need to cross conductors to opposite sides now. Additionally while that cuts down on conductors needed in the actual cable, you still end up needing 8 pins/conductors in the plug, one set of 4 on each side of the plug.
EXPLAIN!
The reply is pretty self-explanatory too. The cable exists in a 4-dimensional space.
It doesn’t necessarily need to be 4-dimensional https://en.m.wikipedia.org/wiki/Spinor
“In geometry and physics, spinors /spɪnər/ are elements of a complex number-based vector space that can be associated with Euclidean space.[b] A spinor transforms linearly when the Euclidean space is subjected to a slight (infinitesimal) rotation,[c] but unlike geometric vectors and tensors, a spinor transforms to its negative when the space rotates through 360° (see picture). It takes a rotation of 720° for a spinor to go back to its original state. This property characterizes spinors: spinors can be viewed as the “square roots” of vectors (although this is inaccurate and may be misleading; they are better viewed as “square roots” of sections of vector bundles – in the case of the exterior algebra bundle of the cotangent bundle, they thus become “square roots” of differential forms).”
Seems pretty self-explanatory to me! /s
