TechStuff Classic: How USB Ports Work

once upon a time, the USB was a novelty. It was a new feature on hardware like laptops and such, and it caused a bit of confusion when it first came out. People weren't used to it. They were used to things like proprietary ports. So we're gonna listen to this classics episode about USB ports. I hope you enjoy. We'll find these ports on computers, smartphones, digital cameras, scanners, printers, and tons of other electronic devices. So what are they,

who invented them? And how do they work? You know, your standard tech stuff type episode. Well, you could just go and read the specification for USB if you really wanted to, and that would give you all the information you need and more. For example, the specification for USB two point zero is a mere six hundred and fifty pages long seems a bit excessive to me, so let's break down the topic tech stuff style. So first, let's talk about what a bus is. In computer terms, a

bus is essentially a conduit for data. Think of it like a hallway that data can pass through. It's a communication pathway that lets different components within a computer or two different devices send data back and forth between each other. That means some buses are internal and facilitate communication within a single device. Other buses are external and allow for the communication of different components like a smartphone to a

computer for example. So inside a computer, you would have a bus connecting components like the microprocessor and a memory storage device like a hard drive. So the computer's operating memory and CPU tend to be very closely tied together, as in its operating memory like the random access memory. That and the CPU are usually real tight. But they still have a bus, and it's usually called the system

bus that connects the two. And just as microprocessors and memory have improved over time, so if buses, they've improved to allow more data to pass through at a single time. Now, keep in mind information is traveling at pretty much the same speed, you know, more or less the speed of light. It's not quite the same, but for the purposes of our argument, it works just fine. So really the question is how much data can you move through the bus simultaneously?

Or if we wanted to use a metaphor, imagine that you have an eye dropper and your friend has a bucket, and you're each taking water from one puddle and walking across a field at the same speed and depositing that water into a little dip in the other end of the field that's going to become the new puddle. So you're just relocating water from one puddle to the other.

Now you're walking at the same speed, so it's not that your friend is going faster than you are, but they can carry more water per trip, so they're delivering more water every time they make this trip, and even though you're both going the same speed. This is why I get a little antsy about data speeds, because it's not really so much about speed. It's more about the amount of data you can carry at a time. That's

kind of what I'm getting at. So if you hear like this computer sends data faster than that computer, the information is still traveling at more or less the same speed depending upon what medium they're using. But it all is down to how much information can pass through at any given time. Now, there are also buses that allow data transfers with sources that are external to the computer. Again, the smartphone is a great example, or a digital camera,

anything like that. The buses facilitate the data transfer, which typically happens over a cable, and there are plenty ways to transmit data wirelessly, but we're just going to concentrate on cables and tethered peripherals today because that's what USB works with, right, That's the protocol is that you're using physical connections. In other episodes, i'll talk about stuff like

Wi Fi or Bluetooth or other methods of transferring data around. Now, before USB ports became a standard way to connect various components to a computer, we had to rely on other types of ports, like parallel and serial ports. Serial parts are se r L ports, not not serial like Captain crunch. They're basic computer connections. They send bytes of data one

bit at a time. So, in case you don't remember basic computer lingo, a byte is eight bits and a bit is a single unit of information in computer speech, it's either a zero or a one, which is kind of like an off on switch. So a byte is eight of these collected together. Serial ports send information one bit at a time one zero or one to one, and then does a whole sequence of those Serial parts had either nine or twenty five pins. The nine pin

connector was a standard for modems. We're talking about the old dial up modems that would connect to your phone line and allow your computer to communicate with the outside world. If you don't know what a dial up modem is, you know, ask your parents. Each pen was designed to allow for communication between the computer and the modem in some way. The twenty five pen connector was meant to become a new standard, but was so much larger than the nine pen connectors that it was a bit hamstrung

from the start. Not everyone adopted it. In fact, a lot of manufacturers just stuck with nine pen peripherals rather than adopt the twenty five pen standard. Serial ports had a range of data transmission speeds from one hundred and fifteen to more than four hundred and fifty kilobits per second, so four hundred and fifty thousand bits per second was

around the upper range of that. Now, some serial ports wouldn't allow for simultaneous operation, which meant that if the computer was sending out data through one serial port, it could not send out data to other serial ports at the same time. It's somewhat problematic if you're trying to do a whole lot of stuff connected to one machine.

Parallel ports were often for stuff like CD burners, printers, scanners, and external hard drives where you wanted to have a faster data transfer because otherwise you're going to be sitting around for a really long time. So it's not that serial ports are necessarily bad for stuff. There are plenty of operations where you only need a little bit of data going between a device and a computer. It doesn't have to be super quote unquote fast because it's just

not data hungry. But other things, like if you want a hard drive, you want something that's going to move data and larger amounts in that amount of time, because otherwise you're going to wait forever every time you try to save a large file to that hard drive or

to retrieve a large file from that hard drive. Now, IBM developed parallel ports specifically to create an interface between a computer and a printer When IBM was first building personal computers, it partnered with a company called Centronics, and Centronics made computers. Centronics had a thirty six pin connector, meaning that the cable ended in a plug, and that plug had thirty six pins arranged in a row that would then plug into a port that had thirty six

holes for those pins. IBM decided to couple this thirty six pin with a second line of pins twenty five in total. So together these two rows of pins were used as the standard for IBM computers, and when other companies began to create clones of the IBM PC, they also created those types of ports. I've got to do

a full episode about IBM clones at some point. I talked about them briefly in a couple of other episodes, but really it's a fascinating thing to hear the story about how other companies were able to take advantage of IBM's design. Now it's called a parallel port because data would flow parallel to each other. Data traveled one byte at a time, not a bit, but a byte a collection of eight bits, which made parallel ports much faster than serial ports or mora acculately, it could send more

data in the same amount of time. Parallel ports could transfer at about one hundred kilobytes per second. But Jonathan, I hear you say. You mentioned that serial ports have a range of one hundred and fifteen to four hundred and fifty kilobits per second. Yeah, I did say that. But parallel ports are sending bytes, not bits, and that bite is that collection of eight bits. So one hundred

kilobytes is the same as approximately eight hundred kilobits. The parallel ports could send more data, though with some peripherals, this amount of data is really unnecessary, which is why serial ports didn't just disappear. They were still useful for certain applications, and they were cheap. So now let's talk about some of the pins in the parallel ports. We

mentioned them in the serial ones. Well, if you were to look at them and number them across the row on both the twenty five pen and the sixty thirty six pin connectors, rather twenty five and thirty six pin connectors, Pens two through nine on those connectors carried those eight bits. Pen one carried a voltage between two point eight and

five volts. The computer would drop the voltage to point five volts whenever it was sending data to a printer or other device, so that was kind of like an alert to a printer to be on the lookout for data. If it detected a voltage drop, it knew that information was incoming, so it's kind of a heads up. Pen ten was reserved for an acknowledge signal, this time sent from the printer to the computer. So this was essentially

gotcha bro. So computer says heads up, printer says gotcha bro, and that lets the computer knows that the message had been received. Other pins were used to let the computer know if the printer was busy, or if it was out of paper or ink or something along those lines, or they were ground connectors as in electrical ground connectors. Future improvements in parallel processors allowed for bi directional communication, meaning that the printer and computer could talk to each other,

not just one way communication. But the original standard only allowed data to flow one way at any given time, So ultimately you would get to parallel ports that could have simultaneous bidirectional communication, but that wasn't how it started. Now. As we created new peripherals for computers, we also created new ports. You'd use expansion cards for your computer, and those would plug into the main circuit board the motherboard

on a computer to create the connection. So if you've never built a machine or ever had to customize one, this might sound a little weird, but here's what it meant. It meant you'd open up a computer case, you'd pop out. Typically there'd be a metal plate on the back side of a computer case that would cover up what would otherwise be just a kind of an oblong hole. You would end up taking the plate off of that so that the hole was open. You would insert a card

into a slot on that main circuit board. It would seat the card properly, so you'd make sure that it was plugged in nice and snug, and you would make sure that you were using the card slot so that the back of the card is lined up with that new hole that you've uncovered on the back of your case. This would allow you to plug in devices externally from the computer. It would just plug in through that hole where the port would be. So the hole is the reason why the plate is there, is to keep the

computer safe from stuff like dust. You know, you don't want to just have a bunch of open areas to your computer or else it can get dusty, which can then mess up the internal mechanisms. Not really even mechanisms. It can just make things overheat and break down and short out a computer if it's really really bad. That's why we have computer fans and stuff like that. It's not just to manage the heat, it's also to manage

the dust. So you take that plate off, you reveal the spot, you've seated the card, you put it all back together, and then you would plug your new peripheral into your new port and you would turn on the computer and find out if it worked or not, and if it didn't work, you had to start troubleshooting. Typically, it would also mean you'd have to turn the computer off again, because the way a lot of these old

systems work, they weren't plug and play. You couldn't hot plug a device into computers for a lot of these ports. That means that you had to actually turned the computer off, plug the device in, turn the computer on, and then it would start to pull information or send information to that device, kind of a primitive way of doing it. And on top of that, some of the devices had

proprietary plugs and ports. For example, in nineteen eighty seven, IBM introduced the EPs slides two port for keyboards and mouses mices miss you know what I mean. The port is circular with six pins arranged in pairs around kind of a rectangular center, and it communicated through a serial protocol, but it had a totally different shape from your typical serial plugs and ports keyboards were similar. And then there's the idea that about plugging stuff while your computer is on. Yeah,

not a thing at those times. A hot port would allow you to plug a device in whether a computer is on or off, and then the PC recognizes that there's a connection and it allows you to use whatever that device is. These old ports, for the most part, did not allow for that unless you had the computer turn on and go through its boot program and then detect all of these peripherals. It just didn't recognize that anything new was attached to it. So why don't we

still depend upon these and other specialized ports. Well, some computers still have special serial or parallel ports, but most of them now have some type of USB port or HDMI port for some displays. And part of the problem is that over the years, the number of peripherals for computer systems grew substantially, but you can only fit so

many ports on a computer. There's only so much physical space you can use, and each port required its own card plugged into a computer's motherboard, so there are only so many slots on a motherboard you could use. Up on top of that, you need to designate special numbers for each card plugging into the motherboard, and that included an interrupt request also known as an IRQ and an

input output address or the IO address. Now, those numbers are hard coded onto cards, so it doesn't mean that you have to come up with a number, it's on the card itself. But that also meant that you could potentially encounter conflicts between different cards for different products. Let's say that you've got a video card from one company

and a totally different peripheral card. Let's say it's for a specific type of scanner from another company, and just by coincidence, they have conflicts in either the IRAQ or the IO address. This could cause issues, and that would sometimes mean that peripherals would become incompatible with one another and that there'd be no way to run both off

the same machine. So you might find that you can have either a display or a scanner attached to this computer, but not both not ideal, and then you had all the different kinds of plugs making it confusing to consumers. You can't just plug any peripheral into any port. That's why older computers frequently have color coded ports and helps the user know which one is for a keyboard versus

a mouse, that kind of thing. So what would be the solution to this, Well, that would be the Universal Serial Bus And I'm going to go into more details about exactly how it pulled it off in just a second, but first let's take a quick break to thank our sponsor. So a much more attractive alternative to these serial and parallel ports is plug and play, which is that concept in which you can just plug a device in using a standardized connector on a standardized port and it just works.

And USB can do that. It can also dramatically increase the number of peripherles you can attach to a single home device, whether it's a hub or a computer or whatever. The USB standard allows up to one hundred and twenty

seven devices to connect to a single source. That would mean you need a few USB hubs to max it out, so you might have one thing plugged into a USB port that actually has five other USB ports in that Then you could expand that it's kind of like plugging like a bunch of power strips into each other in order to maximize the number of power cords that you

can attach to one outlet, only slightly less dangerous. There's not really a huge risk for fire in the case of the one hundred and twenty seven devices attached to a single home computer. The important thing to remember really is that it opens up possibilities for far more connections than parallel or serial ports, which are one customer at a time kind of ports. And plugging a peripheral into a host computer is supposed to be easy with USB, assuming that you have it facing the right way. More

on that in a second. The computer is in charge of communications, so it detects the type of device that gets plugged into any given USB board, and then the computer is supposed to load a compatible driver for whatever that peripheral is. And this is what allows a periphole device like a keyboard or a printer or a digital camera to communicate with the computer in a nice smooth way. Computers downstream data to devices which upstream data to computers

and it's all very civilized, I assure you. There's another really important point. The USB protocol allows for powered connections. That means the ports and cables can carry electricity to power devices as well as a voltage to indicate data transfer, and that was really important. It allowed for options that simplified cable management. If a peripheral could transmit data and receive power through one cable, it could cut down on

some clutter. So this is why you can find lots of little plug in toys and do dads that will attached via a USB cable. So it might be a little desk lamp or a little desktop missile launcher. I've seen those on Think Geek. I really need to get some of those. Hey, if anyone's over at think Geek and you got a few extra little USB missile launchers, send them to how stuff works. I think the office

could really step up its intercompany warfare anyway. Now, we tend to use USB to refer to specific physical things like the ports or the cables, but you have to remember USB is an underlying technology protocol. The physical things we have are specific implementations of that technology, and they are dependent upon various versions of the USB Standard. But the standard is the real heart of USB. It's not a cable, it's not a device, it's not even a computer.

It's the protocol that defines the behavior of USB. Now, right now, as I'm recording this episode, the most recent version of the USB standard is version three point one, and I'll talk more about what that means in just a moment. Before we can really look at where we stand right now, we should probably take a look at where it all got started. And you know me, you know I love my tech history. So how did the USB protocols into being? Wells Zeus on Mount Olympus once

stubbed his toe and from that toe. I wish that were the case, because that would be a cool story. I love Greek mythology. But back in nineteen ninety four, an Intel developer named a jay Bot began working on a solution to this peripheral problem. And at the same time, there was a group called the USB Implementer's Forum Incorporated or USBIF that came into being, and that group included people from Intel, Compac, Apple, Hewitt, Packard, and Microsoft, among others.

This confederation of companies was necessary in order to develop a standard protocol that would work across a vast array of computers and devices. So they wanted to make sure that if anyone incorporated this into their designs, it was incorporated across the board. Otherwise it would be limited in its usefulness. It certainly wouldn't become a universal serial bus.

And they also really wanted to simplify ports. They wanted to reduce the half dozen standards with a single replacement, and ideally it wouldn't matter what you plugged into your computer or which port you used. It would just work. Whether you plugged it in the front the back didn't matter. The computer would automatically recognize it. That's what they wanted, so they had to create something to make it happen. In late nineteen ninety five, they did have something to

show off. They had worked for a full year and they had developed the standard that was called USB one point zero. The protocol only gave a hint at what was to come. It could transmit data at twelve megabits per second, which was much faster than parallel or serial ports,

though sluggish compared to today's technology. The revised USB one point one standard added in another capability of transferring data, but this time at one point five megabits per second, So why would you lower that quote unquote speed or the capacity if you prefer Well, the reason was that some devices just couldn't handle a bandwidth of twelve megabits per second. They didn't need it. They couldn't handle that much.

So you needed to have a throttling mechanism in order to send data at the proper rate to those peripherals. And that was the solution of USB one point one, and one point one got the most US. In those early days, not a whole lot of devices used USB one point zero. Almost everyone was using one point one from as soon as it was available. It just made more sense. The first computer to eschew all other ports in favor of the new USB standard was the iMac

G three in nineteen ninety eight. So Apple led the way. It probably comes as a surprise to absolutely no one out there in the audience, because Apple is known for dumping legacy systems in favor of new technology, at least with their computers, if not their mobile devices. Sometimes they hold back with mobile devices, but they charge ahead with their computers. So with USB devices, it wasn't such a

big deal. Since we're talking about a universal standard. In other cases, Apple has sometimes gone a more proprietary approach, which gets a bit more frustrating because that means you invest in a closed off ecosystem and you can't really use your equipment with anyone else's stuff. In other words, if it's a USB cord, you can use that on an Apple product or a PC where all sorts of other devices that have USB ports and it doesn't matter.

But if Apple goes a proprietary route and the only people making devices and cables are doing it for Apple, then it doesn't do you any good to have that stuff and then encounter a PC. You can't just use that same stuff because the plugs won't fit, the protocols aren't the same, they're not supported by this other piece of equipment. The universal standard gets around that kind of problem. In two thousand, the USB two point zho standard debuted,

and it blew USB one point one out of the water. Now, transfer rates had jumped up to four hundred and eighty megabits per second, which was forty times faster, or rather forty times greater capacity than the previous version. In two thousand and one, USB two point zero became an official standard. In order to ensure backwards compatibility, the USB two point zho standard could also operate at transfer speeds of twelve

megabits per second and one point five megabits per second. Now, that was done to avoid the problem of updating a protocol and making a ton of tech obsolete. At the same time, it also meant that you could plug a USB one point one device into a USB two point zero port, or even use a USB two point zero

cable with a USB one point one port. The only real problem is that if you had a USB two point zero device and you plugged it into a USB one point one port, you might not be able to use the USB two point zero device because it would receive a smaller amount of data over time, So if it needed that faster transfer rate, then the device wouldn't really work well with the USB one point one port.

Otherwise it was pretty much backwards compatible. Also, obviously, if you really wanted to get the most out of everything, you needed to go two point zero across the board. You had to have a two point zero port, you had to have a cable that was two point zero compatible, and you had to have a two point zero device all working together otherwise, you are moving as fast as the slowest member of the team. Right, It's like a relay race team. If one person is slow, that affects

the whole team. Same thing with these components. If one component was USB one point one, twelve megabits per second was as fast as the data could travel, you could not get to that four hundred and eighty speed. USB two point zero also added a feature called USB on the Go that allowed two USB devices to interface through USB without the need for a third component to act

as host. In other words, you could connect two USB two point zero devices directly with each other using the appropriate cable, without having a computer as the go between. So if I had maybe a camera and a phone, I might want to transfer pictures I've taken with my camera onto my phone for some reason. Maybe I want to share them, Maybe I'm just using my phone as sort of an external hard drive. With this USB on the go feature, you could do that without having to

plug both devices into a computer. First, the earlier version of USB, the computer was kind of master control. Everything had to go through it, so this was a big innovation. Around this time we also saw the first USB flash drives, which are sometimes known as thumb drives or pen drives. These are those little storage devices that you plug into a USB port and they feature rewriteable flash based memory.

I got a ton of these from various trips to tech trade shows, and I love them because I could pull the data from that flash drive onto my computer. I could then wipe the flash drive and then use them for all sorts of stuff like documents, pictures, that kind of thing. So a lot of my backups are

on flash drives. The original flash drives could hold a whopping eight megabytes of data, and that's me kind of being a little coy about how primitive our past was, because today you can find flash drives that hold on to hundreds of gigabytes of data, which still sounds kind of crazy to me. There's part of my brain that refuses to acknowledge that you could fit two hundred gigabytes

of data onto something like a thumb drive. Now, with USB three point zero, you get another boost in that capacity that data transfer rate, this time hitting four point eight gigabits per second four point eight billion bits per second. It's also backwards compatible with USB two point zero devices and ports, though again, if you have a USB three point zero device and you connect it to a computer through a USB two point zero port, you're not going

to get the full benefit of the technology. You can't get that four point eight gigabit per second transfer rate. Technically, you probably never would hit that rate anyway. That's sort of the top end of what the data transfer rates are. Usually real world examples are slightly lower than that, but you get what I mean. The USB three point zero standard also allows for simultaneous uploading and downloading on separate wires,

two for transmission, two for receiving data. So this sped things up because you didn't have to wait for a communication to go one route and then for it to come back the other way. You had dedicated wires just for the uploading or downloading of information. It's kind of like having separate lanes on a highway. By doing that, you allow for much faster transfers. And I'll talk more about the wires that you can find in USB cables

in a little bit. One of the things that the USB three point zero protocols allow for is the connection of data hungry peripherals, stuff that needs lots and lots of information in a very short amount of time. So an example that is a high resolution display, because they are constantly refreshing and redrawing the screen so that you can see new stuff. Otherwise it would just be a

series of static pictures very slowly regenerating. You've got to have that super fast data transfer rate otherwise you can't get high definition displays otherwise. So this was a way of creating a plug and play approach to stuff even as sophisticated as a high resolution display. And it also allows for high speed data transfers to storage drives. So if you've ever had to move a large file from an internal drive to an external drive, you know it

can take a long time. Like let's say that you've got an internal drive that's a couple of gigabytes in size, and you have an external data drive and you think, I'm just gonna move everything over to there so i can free up space in my computer. If you've ever done that with a USB two point zero connection, you know it can take a long time. So this dramatically reduced the amount of time it takes to move large

amounts of information around. The USB three point zero protocol helps alleviate that bottleneck that tends to occur at the bus level, though, you're still dependent upon other factors like your computer's processor and the hard drives writing capabilities. Again, it really comes down to what is the slowest element of the collection of technology. Whatever the slowest element is, that's your limiting factor. So really USB improvements are to make sure that the bus stays keeps up to speed

with things like microprocessors and hard drives, that sort of thing. Now. USB three point one I mentioned earlier is the most recent version as of the recording of this podcast. It upped the max data transfer rate again, this time up to ten gigabits per second. At least that's the theoretical top and it debuted in July twenty thirteen. Now, in August twenty fourteen, the usb IF published the specification for USB Type C connector systems. That's the reversible USBC plug.

You can find some smartphones and high end laptops and other devices right now. It's a little different from the previous USB connectors. Also, people tend to conflate the two. They tend to think of USBC and USB three point one being the same thing. They are not. I mentioned earlier that the USB really refers to a protocol, not

a specific technology. Same thing with USB three point one is a technology protocol, a set of standards rules, if you WILLBC is a physical technology that follows those rules and is a cable and port system. It's not in itself three point one. All right, Let's take another quick break to thank our sponsor before I dive into the

madness that is USB connectors. All right, we're going to talk about the different ends of USB cables, which for a lot of people end up being the thing that confuses them or infuriates them the most, especially if you're looking for a very specific USB cable for a very specific device and all you're finding are mini and micro cables. I've been there, I live that life. It hurts. It's

a bit of a puzzler. So let's start with USB two point zero and lower first, because all of those cables have similar connect A USB one point one cable is not gonna pull data the way USB two point ozho can, but they do have the same sort of end connectors that plug into ports. So we begin with Type A plugs and sockets. This is the big standard, the one that you would find on a typical computer pre USB three point zero days, so it's your typical

USB port. The latest models have moved on. But if you probably are familiar with or own a computer that has your just standard USB two point oh style ports, these are the ones that have that big, wide plug for the cables and that have little holes on one side of them that when it slips into your computer, it's supposed to latch on a little bit so that

the cord doesn't easily pop out again. But it's also tends to be the plug that everyone seems to try and plug in upside down first before they flip it around and get it the right way. At least that's my experience. I've worked with USB chords for years, and to this day, I will try and plug it in the wrong way first, probably because I'm not really paying attention. If I just paid attention and looked for the little holes, I could align it properly. But more often than not,

I'm just jabbing away at a computer. You know, an expensive piece of property, like a caveman with a spear jab in a mammoth. That's me when you boil it down to its most basic level with computers, I'm not a proud man. I'm just a guy anyway. That's one of the features of these plugs. There's only one way you can plug them in correctly. You cannot reverse them.

Type B plugs and sockets have a different shape than Type A. These are typically the side of a cable that you would plug into another device like a camera or a microphone in some cases, USB microphones, printers, scanners, that kind of thing. TYPEB socket is an upstrem socket, so that means it has to be on a peripheral because remember computer send information downstream, peripheral send information upstream.

So your typical USB cable has a Type A connector on one end and a Type B connector on the other end. I remember my old blue Snowball mic has a standard Type B port on it. In fact, I've got a blue Snowball mic right in front of me right now. I'm not using it. It was used for a conversation I had online just before I recorded this podcast, and sure enough, it's got a tight B USB connector that square ish connector on the back of it. Now,

let's make things a little more complicated. You also have micro style connectors for USB Type A and Type B connections. Micro Ports can be found on digital cameras, cell phones, smartphones, GPS units, and stuff like that. Then there are USB mini connectors which are actually largelarger than the micro connectors, and those can also be found on other types of

cell phones, digital cameras, and that kind of stuff. So your mini connectors are slightly taller if you were looking at them from the end, Like if you ever had a cell phone that had a mini connector, it's got the ports are slightly taller, and the plugs are slightly taller, and they do not fit into the micro connector ports. Those are thinner, So a mini cable will not plug into a MicroPort, and a micro cable will not plug

into a mini port. And that's the biggest problem I have is because well now it's not the biggest problem I have, because I've got a smartphone that has a USB C cable, adding a whole new plethora of options

for me to mess things up. But back in the day, it was the biggest problem I had because I used to have a cell phone that used the one type of plug, and then I got a cell phone that used it different type of plug, which means I've got all these different cables, and invariably when I was going to charge my phone or I needed to grab a cable for travel that was more common, I would end

up grabbing the wrong type of cable. You'd figure i'd have a fifty to fifty shot, or at least, you know, I would have more of the current type of cable than I did the old type of cable. But for whatever reason, I just had that amazing luck to grab the wrong one every single time. And there are also a few more proprietary approaches to USB connectors, particularly in the world of cameras, so certain brands like Kodak or Sony were using connectors that don't plug into anything else.

The camera has a very specific port on it, and the plug that you have to use is related to that camera, or at least that brand of cameras. This is also incredibly frustrating for people who own lots of technology because if it were a mini or a micro that's a standard, if you lost the cable, it's easy to replace. If you lose a proprietary cable, you have to go back to the manufacturer typically and order an expensive replacement. Keep in mind, they were still using the

USB standard. The underlying technology was the exact same stuff in all the other USB cables. It's just the plug that was different and the port on the device. It was a design choice that ends up forcing you to buy more stuff within a particular manufacturer's collection of products. I might be a little jaded on that, largely because I kept losing chords to digital cameras and it was expensive to replace them. So these days I just use my phone. It makes me so much happier not having

to carry an extra thing around. Anyway, the whole thing sort of defeats the purpose of the universal connector if you ask me, but it does create that market for cords and cables, and only those companies or designated companies that license the technology can actually sell those products, so it's a money maker. Now. Next, you've got USB three point zero Type A and Type B connectors, plus the

USB three point zero MicroB connectors. The basic Type A connector looks very similar to a USB two point zero Type A, except instead of it being having white plastic in it, it's got blue plastic in it. So the blue alert to that you're using a USB three point zero cable, or if you're looking at the port, that it's a port, So they look a lot like USB

two point zero. It is backwards compatible with USB two point zero ports, so you can plug the USB three point zero regular type A plug into a USB two point zero port, but it's going to be going at that use USB two point zero speed. Rather than round pins which earlier USB connectors had inside them, the USB three point zero Type A has flat connectors which stand up to a lot of attachment and removals, so you don't wear out the port or cables quite as quickly.

That's kind of nice. The type B USB three point zero cables look a little different than they are two point zero counterparts, so you cannot plug a USB three point zero type B cable into a USB two point zero Type B port, and that's because the connectors for USB three point zero have more pins, so they're wider, like they're more wide than the USB two point zero kind that actually looks like they almost have two plugs

merged together if you take a look at them. And the ports look a little funky too, because they have this structure where it looks like it's two ports that have been merged together. It's because these connectors have more pins in them, so you can't just use a regular two point oh cable with these devices. The micro connector for a USB three point zero also looks different from the two point zero counterpart, so again you just have

to deal with that. It's one of those things where the trade off to the new technology is that you have to get rid of some of the old stuff that had been universal before. And finally you have the USB Type C connector. So some cables have a Type C connector at both ends, so you've got if you have a USB C cable, it may have a C plug on both ends of it instead of having a Type A or Type B or whatever both ends or

Type C. That works just fine. If you happen to have a laptop that has a C type port in it and you have a smartphone that has a C type port in it, then you can plug the two together no problem. Or if you've got a power adapter that is a plug and it has a C type port, then you can use it as a charging cable. That's what my phone's charging cable is. It's actually a USB

C cable on both ends plugs into an adapter. You plug that into a wall, you plug the other end into your smartphone, and you charge away, and you get to do it at a really fast speed. It recharges very quickly that way, much faster than if I were to plug a USB two point zero to USB C cable into my laptop, because the laptop just can't transfer power at that same rate. So yeah, if I try to plug my phone into my computer, it does charge, but much more slowly than I would if I use

the charge the charging cable. The cables will carry data at a lower transfer rate if you have them plugged into that two point zero style port, depending upon the type of connectors used. Obviously, if it's a C type plug, you would need an adapter, or you would need a computer that had C type ports. You can't plug a C type port into a USB two point zero port, it won't work. They also have a chip incorporated in them,

the USB C cables do. There's at the end of the C cable on that C connector there's actually a microchip incorporated into the wire or the cable really, because the cable is a collection of wires. It has an ID function based on vendor defined messages also known as VDMS, and also a configuration data channel. So in plane speak, the chip gives devices more information about what they're connected to. And that's a lot about connectors. So let's talk about wires.

What would a USB cable look like if you split one open, Well, it depends upon which version of USB you're working with, So if you're working with USB two point zero or earlier, if you split the cable open, you would find four wires inside of it, and normally those wires are color coded red, white, green, and black. The red and black wires are power lines. The red line carries plus five vaults in the black life acts

as a ground wire. The white and green wires are the ones that carry data signals using non return to zero inverted or r ZI encoding. White is technically called DNS and green is technically d plus, and the D stands for data. A USB three point zero cable has some additional wires to contend with. You've still got the four that we just mentioned, and they still perform the same functions in USB three point zero. This is what allows USB three point zero to be backwards compatible with

older USB protocols. But then you also have blue, yellow, purple, and orange wires. The blue and yellow are paired together as a super speed transmitter. Pair of wires, and the purple and orange act as a super speed receiver pair of wires. So these are those dedicated pathways for high speed data transfers. But Jonathan, I hear you ask, what about USBC cables. Do they have any extra wires? Pipe down, I'll get to you. Yeah, they got them. They got

a lot. USBC has eighteen wires. It's probably easiest to go through these by the connectors they correspond with. So Connectors one and sixteen are ground wires, so they're plated in ten TN. They are ground for return power. Connectors two and seventeen are power cables, similar to what you'd find in earlier USB specifications, and they are red. Then you've got a yellow wire at connector eighteen. This one is a power wire for active cables designated as VCON,

whereas the other wires are VBUS wires. All right, So that's one, sixteen, two, seventeen, and eighteen. Let's go back down. Connector three is blue and it's a configuration. Channel four is white and it's the D plus channel. Five is green. It's the D minus channel. That's just like USB two point zero. Connectors six and seven are yellow and brown. And correspond with the first of four shielded differential pairs for high speed data transfers. Eight and nine are the

next two, and they are green and orange. Then you've got ten and eleven. Those are white and black, and then you've got twelve and thirteen those are red and blue connectors. Fourteen and fifteen are red and black and are sideband wires. And that's all of them. That's all the wires that are in the USB C cable. Now.

The important thing to remember is that these wires facilitate powering a peripheral and allowing high speed data transfers, and it only works if you're using the right types of ports, cables and peripherals. So you've got to make sure all of these things are at the highest or the most recent version of USB in order to take advantage of those capabilities. Again, you only go as fast as the

slowest component on the chain, and that's the skinny on USB. Ultimately, it's a story about several powerful entities in the computer industry getting together to streamline what had become an increasingly frustrating consumer experience. I think the solution is actually pretty elegant. It's complex, and it's a little difficult to understand. I didn't dive too deeply into the tech of it because to do so would have taken a lot more time

to explain all the different fundamental principles. I will say that the switch to USBC has irritated some people because it's creating new connectors, so it means that you can't use your old cables for a lot of this stuff. That's part of the growing pains of technology. If we rely upon existing designs, we won't be able to enjoy those faster speeds or other features like power management and

other improvements over time. Another when I got my latest smartphone that uses that USBC connector, I was a little irritated at first. I knew that I had to buy new USBC cables if I was going to go traveling. I couldn't just one of the billion USB minis or micros that I had because they wouldn't work. And I still don't have a computer that has a USB C port, so I only have that one power adapter that I

can use. I don't have anything else that uses USBC right now, so I really only enjoy those faster speeds when I plug in the power adapter. But assuming I upgrade to current technological standards. I'm sure I'll be pleased as punch with the USBC, which will probably happen right around the time someone debuts USBD or whatever comes next, and I'll still be behind the times, and so it goes.

That's it for the tech Stuff classic episode how USB Ports Work, which originally published on April twenty first, twenty seventeen. Hope you enjoyed that. Obviously we could do another follow up on there. USBC has been a huge thing over the last few years, and yeah, there are a lot of things to talk about when it comes to USB technology and how it has advanced over the years. So maybe I'll do a follow up episode at some point, But until then, I hope you are all well and

I'll talk to you again really soon. Tech Stuff is an iHeartRadio production. For more podcasts from iHeartRadio, visit the iHeartRadio app, Apple Podcasts, or wherever you listen to your favorite shows.