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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)

#171

Post by jpeanuts »

polishdude20 wrote: post #103
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.

Let's go further and get a hexagonal one.

This is not so crazy - this was exactly the progression in screw drives. First came slotted screws (2-fold rotational symmetry), then Phillips/posidrive/Robertson (4-fold), and now Torx (6-fold). Going back to slotted now is actually irritating.

Of course the constraints and trade-offs are very different... still it would be a piece of cake to plug them in on the backside of a box with your eyes closed.

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

#172

Post by lxgr »

josefx wrote: post #106
jawns wrote: post #15

Earlier quoted context omitted.

I agree that there was more that could have been done to signal correct orientation. But an additional wrinkle is that the orientation of the port itself was not static. On laptops and desktops, it was horizontal. On certain other devices, it was vertical. Often these ports were in hard-to-reach or hard-to-see places, and having to reconcile the orientation in each case probably added to the frustration.

> or hard-to-see places Which brings up the idea of not making it size compatible with the network port.

As somebody who keeps inserting the USB-C charger cable into the SD card slot of the new MBP, I couldn't agree more.

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

#173

Post by sokoloff »

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.

I have many USB-C cables that don't behave like other USB-C cables. Just this past week, I had to buy another cable for my son's desk setup because of the many USB-C cables I had, I was out of the ones that would carry 4K video and USB-C 80+W PD to his laptop at the same time. (I had a couple that worked, but they were in use for my wife and I, and the couple handfuls of others I had were capable of zero or one of those two functions.)

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

#174

Post by lxgr »

gsich wrote: post #73
donatj wrote: post #6

It didn't really need to go in either way. It just needed to not be rotationally symmetrical while only going in one way. Firewire only went in one way but it was never an issue because it's shape conveyed a clear orientation.

Firewire ports can be inserted the wrong way, if the material cheapens out you are in bad luck. Wrong polarity will most likely kill the other device.

> Firewire ports can be inserted the wrong way

Hopefully only with a hammer!?

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

#175

Post by dboreham »

gzalo wrote: post #157
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…

> Then you implement auto crossover detection, dwhich had been around for years Mdi-x/auto crossover for ethernet was introduced in 1999, that is after USB (1996) was designed, not sure of the technique was known at that time

There were auto-crossover RS-232 boxes going back deep into the 1980s.

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

#176

Post by lxgr »

northwest65 wrote: post #84
gsich wrote: post #72

Earlier quoted context omitted.

Logo up is no help when you try to do it in the dark.

You can feel it with the pad of your thumb.

I just looked at my nearest USB-A plug: There's no logo on either side.

I'm also almost certain I had connectors with a different logo on either side.

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

#177

Post by Hackbraten »

jmbwell wrote: post #83
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…

3) The most fragile part (the wafer in the center of the receptacle) is on the expensive-to-repair device, while the least fragile part is on the cheap-to-replace cable. HDMI makes this same mistake. With USB-A, at least the plastic part on the device is relatively robust, and with Lightning, both plug and socket were rather robust (albeit prone to debris incursion). With older pin-type connectors like VGA and DVI, t…

> The most fragile part (the wafer in the center of the receptacle) is on the expensive-to-repair device, while the least fragile part is on the cheap-to-replace cable.

Why do you think that the wafer is the most fragile part?

One might argue that the latch mechanism would be the part most exposed to wear and tear due to mechanical stress incurred by plugging and removing. Those side latches are located in the plug, not in the receptacle.

See also figure 3-14 in the USB-C spec [1].

[1]: https://www.usb.org/sites/default/files/USB%20Type-C%20Spec%...

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

#178

Post by postmodest »

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)

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

#179

Post by lxgr »

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…

> trying in vain to reach behind a heavy computer and unscrew the two jammed retaining bolts holding in a serial, parallel, scsi, vga, or DVI plug with slippery bent plastic jacketed heads

Oh yes, that brings back very bad memories.

Only gradually did it dawn on me that nothing really bad actually happens if I didn't screw the connectors tight on DVI/VGA etc. :)

(Yes, these are technically not plug-and-play, but the occasional disconnect sure beat all the banging my head on the desk and swearing profusely every time I changed something with my personal setup.)

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

#180

Post by dpratt71 »

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.

It sounds like we'd be better off not knowing about this law. Thanks.
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