Why did USB start off with so many variants, and now that USB C is gaining steam, can it replace the rest of them?

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I don’t know how we got to where we did, but aren’t you glad USB C came along?

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Anonymous 0 Comments


Anonymous 0 Comments

It’s so much worse of a nightmare than you realize, usb c is just a connector standard, there is a whole other wire standard so you can get like, usb2 with usb c and usb power only with usb c so it looks like they reduced to one standard but there is still like ten cables that can look identical

Anonymous 0 Comments

Okay, let’s start out from USB 1 and USB2. The design behind them is that, just like the pre-USB ports, ports can only go one way, as they want to keep the cable/connector count low (plus carry over from the old ports design). Because it’s designed from a PoV of PC, and things are determined by hardwares, it has USB-A on the host side, and USB-B on the device side. Also, the more wire you have, the more interference/noise can come about.

Then small consumer device comes. At first it was USB-mini (variant of B), then you have USB-micro (another variant of B)

Then USB3 comes. At first its B variants are extension of the large size USB-B and USB-micro… since IEEE loves backward compatibility.

But then, as USB start to expand, other developers also want to utilize a universal plug for other protocols, such as Thunderbolt and Displayport – maybe even use it to deliver high power too! Then they want to forget about the host-device relationship by plug type, instead is determined by software. And since cable/connectors are so cheap, and technology can eliminate all the issues, why not make it reversible? Thus comes USB-C

Above is just for keeping within USB. I am ignoring for example Apple’s Lighning, etc – but for this kind, it was so to force people to adapt to their standard (and thus pay more money). Why they can do that? Because people are willing to go in for prestige.

Anonymous 0 Comments

USB was originally designed in 1995. It had two connector shapes: USB A, used for power-supplying hosts, and USB B, for power-consuming devices. These connectors were pretty big, so mini and eventually micro versions were introduced. USB 3.0 needed more pins, so new versions of standard-size A and B and micro-B were introduced.

In 2012, technology had developed enough that separate connector shapes weren’t needed based on which end supplied power (the devices could automatically figure it out). USB C can replace any previous USB connector.

Anonymous 0 Comments

USB was a attempt to be a “universal” connector. Before USB, you have a whole bunch of different cables and connectors, some small some massive. Parallel, Serial, PS/2, 9-PIN, power etc.

As USB became the standard and replaced all the older types, it went through a bunch of revision to increase the amount of data it could handle. Then you had new physical shapes to fit the needs of smaller devices. Mini USB, Micro USB.

USB C is the equivalent of the original USB 1.0. A universal connector to replace all the older ones.

Anonymous 0 Comments

Let’s start at the very beginning. USB *actually* started off with just 2 variants: USB-A and USB-B. The idea was that a USB cable would *always* have USB-A on one end, and USB-B on the other. The USB-A side would be the one to say “I’m here!” and send out power. The USB-B side would just wait and do nothing until it got suitable communications from the USB-A side. The nice part of this is that it makes everything really simple. If you’re on the USB-A side, you don’t have to do the work to try and see if anyone is trying to talk to you. If you’re the USB-B side, you don’t have to know how to start conversations. You also don’t have to worry about power coming in when you’re trying to send it out. Back in 1995, keeping it simple like this was good – we will come back to this.

These connectors were made in 1995, for the relatively large machines of the time – thick laptops and desktop computers with plenty of room. So, making them large wasn’t an issue, your peripherals would generally be relatively large too or have the cable built in.

Then, devices started getting smaller. They introduced a new, smaller connector, “mini USB”. They made a mini version of USB A and USB B. The wires were the same, just the plug was smaller. This wasn’t small enough for a lot of uses, so they wanted to make it even smaller – and they did, introducing micro USB, which was even *smaller* and had micro A and micro B

Then, they wanted to make an even faster version of USB… But the wires they had just couldn’t take it. The first versions of USB had just four wires, and only two of them carried data, not great. So they needed to add more wires… But most of the connectors were just too small! They had made all those mini and micro versions too small to add more wires, so they had to make the connector bigger in some way (but ensure you could put an old plug in a new socket). They didn’t bother making new versions with extra wires for mini USB A, mini USB B or micro USB A, because they weren’t used that much – but the shape of the new version of standard USB B and micro USB B was different to the old one.

Now, we come to around 2014. This whole situation kinda sucks, and you can’t make USB “universal” the way device manufacturers want to – it’s inherently really hard to use the same port to charge a device *and* send data out to a connected device, all the solutions kinda suck. At the same time, those concerns we had 20 years ago about “but it’s so hard to have everything listen and know how to start communications” aren’t as major, because of how much more computational power everything has. So, they decide to make *one* connector that can *actually* do it all – it can start the conversation, it can just reply, it can send out power or it can receive it. They couldn’t make it back then because computers weren’t as powerful, but they can now!

Anonymous 0 Comments

I love the reference to “USB starting with so many variants.” You just haven’t gone back far enough to see that it did start with one variant, fractured, then has re-merged into USB C.

What will further melt your brain is looking deeper into the USB protocols vs the connector type. What’s the difference between USB 3.0, 3.1 and 3.2? Can I identify these protocols by port? Does any cable that can plug into a USB 3.2 port guarantee USB 3.2 speeds?

As to “Can USB C replace the rest of them?” Yes. For now. But why did USB C come about in the first place? Through the requirement for a more dense pin configuration for a higher bandwidth connection. So USB C will replace them all, until we need more pins on the port and USB D is rolled out. Rinse and repeat for infinity.

Anonymous 0 Comments

The new USB-C is probably the only new “standard” that noticeably works better. From what I understand it is capable of higher voltage and easily charges even the most finicky cell phones (looking at you Apple).

Anonymous 0 Comments

Key point to know:

USB-C is a connector standard. It can carry power, HDMI video, thunderbolt (kind of PCIe), and USB (universal serial bus, used for peripherals like mice, keyboards and storage).

Power can be simply the old standard 5V, or, if both ends support it, they can go to 100W using 20V.

Not every computer/phone/tablet supports every mode. About the only thing you can be sure about is the usb side of things and 5V power.

So to answer OP, yes, USB-C can replace old USB tech and more.

Anonymous 0 Comments

A couple of excellent explanations for the number of variations, so I’ll leave that alone.

The interesting part is WHY we have USB. Apple had already invented IEEE1394 (FireWire) which was technically superior in almost every way. Problem was…Apple wanted to charge implementers upwards of $1 PER-PORT to use it. That’s a lot, so several companies got together (under Intel’s guidance) and created a royalty-free semi-alternative interface and USB was born.