Earlier quoted context omitted.
For an example of an asymmetrical "rectangle", look at HDMI: https://en.wikipedia.org/wiki/HDMI#/media/File:HDMI_connecto...
FireWire was great for that. I loved that connector.
Wasn't it based on the GB link cable?
USB inventor explains why the connector was not designed to be reversible (2019)
431–440 of 544 posts
Re: USB inventor explains why the connector was not designed to be reversible (2019)
#432I used to struggle with USB-A plugs until I made it a point to actually look and pay attention. 99% of all plugs are labeled and logo side faces up. For devices that have a natural orientation (e.g. laptop), it always goes one way. For mating two cables, just look at where the male PCB in one is.
Turns out that plugging in USB-A cables is a skill you can learn in 5 seconds.
Re: USB inventor explains why the connector was not designed to be reversible (2019)
#433I 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…
Everyone here constantly complains about USB-C any time it comes up, but my experience has been that it's fucking awesome that so many of my devices have the same cable type: phone, tablet, laptops, USB battery packs, VR headset, Switch, Deck, various game controllers, various retro game handhelds, portable monitor, antigen COVID-19 detector, car battery starter, all kinds of stuff really.
And now that lightning is going the way of the dodo, soon I'll finally be able to consolidate to basically just the one cable type for trips.
Re: USB inventor explains why the connector was not designed to be reversible (2019)
#434Earlier quoted context omitted.
> I'm reluctant to consider shoddy or noncompliant implementations as counting against a technology. I find it interesting that it is typically done with programming languages. "This programming languages allows people to write complicated, unreadable code, hence the language is bad".
In fairness there are plenty of people who think one should not consider it a language flaw if you can shoot yourself in the foot. See: basically every C programmer.
That's my point: where do you put the limit? A gun allows you to shoot yourself in the foot. Does that make it a bad gun? I think most of us would agree here: if you are at high risk of shooting yourself in the foot, you should not be given a gun.
Nobody ever says "oh, this laptop is bad, because if you take it in the bath you will probably break it". But for some reason, for professional programmers, we consider it is absolutely unbearable to request that they know their tool.
Re: USB inventor explains why the connector was not designed to be reversible (2019)
#435Earlier quoted context omitted.
Easily going into the early 2000s. I remember trying to setup LAN parties in 2004/2005, where the wrong combination of patch or normal cable with hub/switch/PC made everything a nightmare.
I found a few patch cables mixed in with regular cables. one day, i got so tired of messing with them, i cut the cables and put them in the trash. i could have just trashed, them, but that didn't feel right. i mean, what if someone were to go dumpster diving. the curse would then be on them.
Uh? They're trivial to tell apart, just put the RJ45 jacks side by side and look at the colors of the wires going in?
Same sequence -> Straight ethernet cable
Same sequence except for 1 swapped pair -> Probably a crossover Ethernet cable
Inverted sequence -> ISDN cable, burn it.
Also (apart from the ISDN cables) - it hasn't mattered for close to quarter of a century, all switches and NICs are auto-MDI-X nowadays, why throw away the stuff.
Re: USB inventor explains why the connector was not designed to be reversible (2019)
#436Earlier quoted context omitted.
> 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. I disagree. When connecting an HDMI cable I sometimes have issues, especially if in a weird angle. However I do concede is faster to connect an HDM…
Yeah, I want the connector that can be attached by only moving the TV a few inches, just enough to get my hand to fit and feel around, not something I have to rearrange the furniture for and break out some headlight to see which direction the cable is oriented. With BNC cables, I could do it with my eyes closed.
Tbh, humanity should've just used SDI for everything.
Re: USB inventor explains why the connector was not designed to be reversible (2019)
#437Earlier quoted context omitted.
Even having a bump on the rubber moulding as part of the standard would have solved the problem.
The USB symbol goes on top, IIRC. Edit: ninja'd by an enormous amount of people elsewhere in the thread, gah.
> The USB symbol goes on top, IIRC.
For some values of "top"; that is, some device manufacturers install the socket upside-down.
Re: USB inventor explains why the connector was not designed to be reversible (2019)
#438Where all my autistic nerds at who look at the connector before they stick it in, and remember which way all their connectors are facing? hands up
Re: USB inventor explains why the connector was not designed to be reversible (2019)
#439Earlier quoted context omitted.
Can't that square metal be used as ground?
You don’t always want the shield coupled to the signal ground. If it’s coupled on both sides then you can have all kinds of fun problems. Ideally, the shield should be connected to the ground on one end
> Ideally, the shield should be connected to the ground on one end
Depends on the signal. With low-frequency stuff (like audio) you want to ground the shield on one side to avoid ground loops, but with high-frequency stuff (USB 3, for example) you definitely want to ground the shield on both sides: if you don't, you end up creating an antenna which is really bad for your EMI performance.
USB 1.x happens to be at an in-between point where neither issue is a big deal. The connector spec literally says "use accepted industry practices", so either approach is fine if it manages to pass emissions testing.
Re: USB inventor explains why the connector was not designed to be reversible (2019)
#440> 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
Not really relevant.
Ethernet needs crossover because it has dedicated transmit/receive pairs, but USB 1.x/2.0 uses a single wire pair for both tx & rx. Ethernet crossover is pretty much identical to serial null modem cables, and those were around for a few decades by then.
USB "crossover" of the single differential wire pair would be an inversion of 0 and 1. Pretty trivial to do once you figure out a way to communicate crossover or not.