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USB inventor explains why the connector was not designed to be reversible (2019)

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Re: USB inventor explains why the connector was not designed to be reversible (2019)

#511

Post by dheera »

ilyt wrote: post #505
dheera wrote: post #386

Earlier quoted context omitted.

Or just put + and - through a rectifier and you don't need an extra pin. Data lines -- use differential signalling and polarity determined by whether +/- got reversed by the rectifier or not. Or do like Comcast does and put all bidirectional data through 1 conductor at multi-gigabit speeds.

Maybe if you have no clue about electronics don't talk about electronics... > Or do like Comcast does and put all bidirectional data through 1 conductor at multi-gigabit speeds. And how much modem's transceiver cost ? And how does that compare to cost of computer mouse or other cheap USB peripherals.

They'll cost 1/100 the price if every USB port in the world uses them. Auto parts for common models of cars are so incredibly cheap for a reason.

Re: USB inventor explains why the connector was not designed to be reversible (2019)

#512

Post by smoldesu »

scarface_74 wrote: post #510
smoldesu wrote: post #506

Earlier quoted context omitted.

> if HN commenters can’t figure this stuff out, what are the chances that normal people can? Plugging it in would probably be a good start. I can't name a single time where I've ever mistakenly identified a USB-C cable. Sometimes I've plugged it in when it wasn't connected to the wall, but I think worrying about non-compliant USB-C cables is no more relevant than caring about non-MFI certified Lightning cables.

Until you take a USB C cable with you in your laptop bag to connect with your portable USB C external monitor that gets power and video from one USB C cable and find out you have the wrong USB C cable with you.

Hate to say it, but it's entirely PEBCAK to not select a Thunderbolt cable when they want DisplayPort alt-mode. It's why the damn cable and marketing even exists in the first place.

99% of people only care about power (and optionally data), so that's what the spec focuses on.

Re: USB inventor explains why the connector was not designed to be reversible (2019)

#513

Post by ilyt »

dheera wrote: post #511
ilyt wrote: post #505

Earlier quoted context omitted.

Maybe if you have no clue about electronics don't talk about electronics... > Or do like Comcast does and put all bidirectional data through 1 conductor at multi-gigabit speeds. And how much modem's transceiver cost ? And how does that compare to cost of computer mouse or other cheap USB peripherals.

They'll cost 1/100 the price if every USB port in the world uses them. Auto parts for common models of cars are so incredibly cheap for a reason.

USB1 was designed in times where transistors were significantly more expensive. And in times where laptops or phones or any other situation when you disconnected peripherals were far less common. Like, it still was improvement over PS/2.

It's also not just few transistors to flip the lines around, it's also the logic to drive that

Re: USB inventor explains why the connector was not designed to be reversible (2019)

#514

Post by dheera »

ilyt wrote: post #513
dheera wrote: post #511

Earlier quoted context omitted.

They'll cost 1/100 the price if every USB port in the world uses them. Auto parts for common models of cars are so incredibly cheap for a reason.

USB1 was designed in times where transistors were significantly more expensive. And in times where laptops or phones or any other situation when you disconnected peripherals were far less common. Like, it still was improvement over PS/2. It's also not just few transistors to flip the lines around, it's also the logic to drive that

Y'all are talking as if you were in the vacuum tube era.

There were 42 million transistors in a Pentium 4, I'm sure they could have put a few thousand per USB port if they thunk optimistically instead of pessimistically.

When USB came out we already had some very crude 3D realtime rendering already at that time available to mass consumers, I'm sure we could have figured out how to flip power on a port if we put our minds to it.

Think "how can we make shit happen" instead of excuses of why it's hard.

It's by doing hard things that we got to the 80 billion transistors of modern GPUs.

Re: USB inventor explains why the connector was not designed to be reversible (2019)

#515

Post by scarface_74 »

smoldesu wrote: post #512
scarface_74 wrote: post #510

Earlier quoted context omitted.

Until you take a USB C cable with you in your laptop bag to connect with your portable USB C external monitor that gets power and video from one USB C cable and find out you have the wrong USB C cable with you.

Hate to say it, but it's entirely PEBCAK to not select a Thunderbolt cable when they want DisplayPort alt-mode. It's why the damn cable and marketing even exists in the first place. 99% of people only care about power (and optionally data), so that's what the spec focuses on.

And you’re also proving my point. You don’t need a thunderbolt cable to supper video out….

Re: USB inventor explains why the connector was not designed to be reversible (2019)

#516

Post by alanbernstein »

ianburrell wrote: post #107
alanbernstein wrote: post #86

Earlier quoted context omitted.

I own a usb-c male to usb-c female extension cable that I connect to a yubikey. The yubikey only works in one orientation. I don't have any other bits to test hypotheses with, but I believe the cable was made with the symmetry problem described above.

Then throw it away, it is broken. There is no way to prevent junk from not implementing the standard. The solution is not buying junk.

It is not broken. It is the best solution to a problem, even if it is imperfect.

It seems that the committee behind the spec was somehow unable to learn from decades of experience, and did not predict that people would want extension cables, and that companies would make them. That's not an actual problem for me. Not being able to reach my yubikey when I'm using my laptop at my desk, is a problem.

Re: USB inventor explains why the connector was not designed to be reversible (2019)

#517

Post by tommiegannert »

perilunar wrote: post #479
tommiegannert wrote: post #58

If we're not going back to circular slip-ring connectors that allow rotation (like TRS or DC plugs,) then the step after the +-90 -reversible USB-C is a triangular one. So you only need to rotate it +-30 if you got it wrong. Now I really want a triangular connector. Like in alien-tech movies.

What's wrong with circular? There's no wrong way to plug it in.

Nothing to me, for the same reason you gave. I'd love to see them making a comeback.

My guess is they won't come back because modern connectors are so thin that if you made them equally narrow, they'd break/bend easily. (And yes, 3.5mm really is too thick to be a standard size, e.g. in wearables. The outer thickness of the USB-C socket is 3.3mm.)

Re: USB inventor explains why the connector was not designed to be reversible (2019)

#518

Post by tommiegannert »

crote wrote: post #466
tommiegannert wrote: post #57

Earlier quoted context omitted.

Many of the TRS connectors have a built-in switch to (originally) disconnect the internal speaker. It would probably have been easy to extend that concept to isolate all contacts until the tip hits the bottom.

That's not going to save you when you try to plug in the device-side connector with the computer-side already connected (and therefore already applying power to the cable).

Why? It's also disconnected at the device's socket until fully seated?

Re: USB inventor explains why the connector was not designed to be reversible (2019)

#519

Post by HeyLaughingBoy »

kybernetikos wrote: post #250
snakeyjake wrote: post #140

> Making USB reversible to begin with would have necessitated twice as many wires and twice as many circuits, and would have doubled the cost. This is... not correct. You can make USB reversible with 1 extra pin and 1 extra wire. Grounds on pins 1 and 5, data on pins 2 and 4, and VCC on pin 3. Then have those pins on both sides of the plug and a socket with a single set of contacts on one side. That's BASICALLY what…

Couldn't original USB have used TRRS? That's better than reversible - an infinite number of orientations are allowed.

TR/TRRS have very small contact patches since you're connecting to the tangent of a circle. That's not good for anything carrying more than a very small current. And even then, it can be an unreliable contact.

Re: USB inventor explains why the connector was not designed to be reversible (2019)

#520

Post by nerpderp82 »

bigstrat2003 wrote: post #508
nerpderp82 wrote: post #492

Earlier quoted context omitted.

As a repair shop, it is your job to repair the broken thing, not just sell them a new one. A big shielded molded cable can be fixed, either at the connector or replacing the whole cable where it terminates into the PCB. If I had known about a shop disposing of 500-700$ monitors with bad cables, I would have made a fortune.

As I have said, I had no idea you could fix such a thing. Hell I didn't even know that until this very thread, much less 20 years ago. As such it was not in the least malicious (ignorant perhaps, but that's a separate thing). In any case, your unfounded criticism of my moral character is really irrelevant to the main point I made: it was totally possible to fuck up plugging in D-sub connectors, and I witnessed multip…

I apologize, my comment was too strong. I am sure many shops did this, probably because they got into retail when the home computer market was booming and weren't yet skilled in repair.
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