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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)

#181

Post by Cannabat »

Ajedi32 wrote: post #74
lesuorac wrote: post #13

I know everybody is still on the high from USB-C but I'm still going to go on the record it will be one of the biggest disasters in cable history. 1) There's going to be video-only cables; low-voltage only cables; etc and this time everything is usb-c so you can literally only tell which ables work by testing all of the dozen cables instead of the 1-2 USB-As you have. 2) The connector is symmetrical but the pins aren…

I had to do a double take after reading this comment to make sure I wasn't reading an old thread from 2014 or something. USB-C has been out for years now and neither of these predictions have come to pass. Your comment aged poorly before you even finished writing it. USB-C isn't without its problems, but neither of those are one of them.

You’ve been fortunate (or far more clued in to usb standards than just about everyone) if you don’t already have multiple usb c cables with different capabilities.

It’s possible for noncompliant usb c cable to fry electronics.

I don’t know of any other connector standard where the connector doesn’t clearly indicate or imply the cable’s capabilities. I’m sure they exist, but generally for consumer electronics if a cable fits, it works. Except for usb c.

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

#182

Post by cloudwalk9 »

parsimo2010 wrote: post #150
bravetraveler wrote: post #123

Earlier quoted context omitted.

I've found a trick but have trouble explaining it to people - especially if they haven't build a computer before. The plastic bit inside of the plug usually goes on the side facing whatever board it's interfacing with. For example, looking straight on from the back of an ATX case, it's usually on the left side - where the motherboard mounts Front panel connectors are anarchy... but at least they're usually visible

Another trick is that the USB standard says the USB logo should be facing up, so you should always try it first with the logo facing up. Not every device follows that standard and not every device has a clear top/bottom, but this really cuts down on the proportion of failed attempts.

The pattern on the aluminum of the plug is also helpful in cases of predictable slot orientation (like a laptop, except a Dell Latitude from back in the day that had upright connectors on the back unless I'm misremembering). The side without the seam down the middle and instead a tiny rectangular cutout center but slightly lower than the other two cutouts, should face up. In the dark, the seam can be felt by lightly scraping with a fingernail.

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

#183

Post by p1mrx »

npunt wrote: post #139
lesuorac wrote: post #13

I know everybody is still on the high from USB-C but I'm still going to go on the record it will be one of the biggest disasters in cable history. 1) There's going to be video-only cables; low-voltage only cables; etc and this time everything is usb-c so you can literally only tell which ables work by testing all of the dozen cables instead of the 1-2 USB-As you have. 2) The connector is symmetrical but the pins aren…

I think this is a bit hyperbolic. Once you try to implement any standard in practice to billions of people & devices you're going to find the same constraints and similar trade-offs everywhere. Manufacturers are going to cheap out, always . There's no way around the fact that goods can get on the market claiming a thing that it doesn't do (perfectly) in practice. Tech is littered with semi-compliance. I hate to kick…

USB-IF should publish a table of every possible cable/adapter/receptacle type, with a short alphanumeric code that can be printed or molded onto the connector.

The set of permutations is too large to fit into an icon, but a lookup table allows for unlimited detail.

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

#184

Post by userbinator »

postmodest wrote: post #178
aranchelk wrote: post #164

My take on USB-A: aside from audio connectors that have axial symmetry (and have no meaningful orientation), I never used any reversible computer cables prior to USB-C, and that’s not the main issue. Nor is it the axis of symmetry of the casing allowing failed upside down plugin attempts. The shitty part of USB-A is that the tactile feedback of being slightly misaligned is identical to it being upside down. My experi…

At least PS/2 cables were mostly made with "keyed" rubber jackets where one side was flat and the other rounded, so in the dark you could tell which way was up. (Though, that keyboard and mouse were different ports was stupid, so it loses points there)

Keyboard was always the one closest to the mobo, since it was there first (and was originally a larger, more robust DIN connector); the mouse piggybacked on top of that later.

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

#185

Post by agumonkey »

jowea wrote: post #141
agumonkey wrote: post #122

Earlier quoted context omitted.

The funniest part is that it still takes 3 tries even when you know what you just said.

http://www.extremetech.com/wp-content/uploads/2015/01/lLcxrw...

hehe, right on

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

#186

Post by lxgr »

lesuorac wrote: post #13

I know everybody is still on the high from USB-C but I'm still going to go on the record it will be one of the biggest disasters in cable history. 1) There's going to be video-only cables; low-voltage only cables; etc and this time everything is usb-c so you can literally only tell which ables work by testing all of the dozen cables instead of the 1-2 USB-As you have. 2) The connector is symmetrical but the pins aren…

> There's going to be video-only cables

There is no such thing for USB-C.

> low-voltage only cables

As far as I know, only the amperage is negotiated; every compliant cable needs to support at least 20 V.

And even then, the minimum is also 3 A, which allows for 60 W to be carried on even the cheapest cables – enough for many use cases. I actually like having lighter and more flexible cables for most of my devices.

> The connector is symmetrical but the pins aren't. You can see a wiring scheme of how symmetry is handled [1]; literally manufactures are going to cheap out and not do that and you have 1-way USB-C cables without any kind of orientation markers.

With all the many USB-C headaches I’ve heard of (and only very rarely encountered myself), I’ve never seen that happen.

The most common problem must be using a USB 2 only cable for a use case that requires USB 3 speeds and/or video.

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

#187

Post by agumonkey »

pdpi wrote: post #134
agumonkey wrote: post #122

Earlier quoted context omitted.

The funniest part is that it still takes 3 tries even when you know what you just said.

Hofstadter's Law: It always takes longer than you expect, even when you take into account Hofstadter's Law.

I had a variant of that for covid. The contagion curve plotted daily rates even taking into account people knowing about the contagion curve.

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

#188

Post by dboreham »

"Ajay Bhatt, widely considered the inventor of USB..."

Interesting. I had been told long ago that my fellow-Inmosian Dave Wooten was instrumental. And sure enough:

"David was principal architect for USB 1.0, USB 1.1, and USB 2.0."

from https://ece.ncsu.edu/honor/david-wooten/

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

#189

Post by lxgr »

Cannabat wrote: post #181
Ajedi32 wrote: post #74

Earlier quoted context omitted.

I had to do a double take after reading this comment to make sure I wasn't reading an old thread from 2014 or something. USB-C has been out for years now and neither of these predictions have come to pass. Your comment aged poorly before you even finished writing it. USB-C isn't without its problems, but neither of those are one of them.

You’ve been fortunate (or far more clued in to usb standards than just about everyone) if you don’t already have multiple usb c cables with different capabilities. It’s possible for noncompliant usb c cable to fry electronics. I don’t know of any other connector standard where the connector doesn’t clearly indicate or imply the cable’s capabilities. I’m sure they exist, but generally for consumer electronics if a cab…

USB-C problems surely exist, but I have never heard of single-side only plugs, and video-only cables simply don’t exist, yet these are GPs specific concerns.

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

#190

Post by whoooooo123 »

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…

The problem with USB-a isn't that it's non reversible, it's that it's non-reversible _and_ rectangular, so it's not clear at a glance which way round it should go.

All they had to do was make the connector have a non-symmetrical shape so that it's immediately obvious which way round it goes when you pick it up - you could do it without even looking. Think of how much time we'd have collectively saved with this minor design change.

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