USB inventor explains why the connector was not designed to be reversible (2019)
pcgamer.com
pcgamer.com
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 Apple did with lightning.
Then you implement auto crossover detection, (edit: Gah! you don't even have to do that just flip the flipping wires) which had been around for years and is dirt cheap, in the hub. It would have been like, six, more transistors in the hub IC.
edit: I completely forgot that reversible USB 2.0 plugs already exist and use a simpler (and cheaper) method. They just tend not to be so reliable because of the thinner materials and the fact that they're not spec-compliant so they tend to be grey market jobs made for the lowest price possible.
Here is one: https://www.amazon.com/Tripp-Lite-Universal-Reversible-UR050...
No doubling of wires or circuits required, just a thin double-sided PCB.
Was the connector form-factor inherited from an earlier project and the players didn't want to design a new one?
https://www.pcgamer.com/youre-telling-me-we-could-have-had-r...
https://2b.com.eg/en/2b-cv177-cable-usb-type-a-reversible-pl...
> Incidentally, the late Steve Jobs deserves a tip-of-the-hat for helping USB become a long-lasting standard. It was in 1998 that USB made some real headway, courtesy of the iMac G3, the first computer to ship with only USB ports for external devices (there were no serial or parallel ports). That came three years after USB 1.0 debuted, with a data rate of 12Mbps.
Also PCgamer:
> Given that it was a protocol designed to counter the typically Apple expense of sticking Firewire onto a motherboard, cost was the biggest reason for the eventual success of USB as a thing
Apple started building FireWire 400 into Macs when 12Mbps USB 1.0 was not really an equivalent. USB 2.0 didn't make the cut for the first generation iPod but was supported on subsequent models.
I remember presenting this in a project as an undergraduate and I was challenged by the lecturer that it would be highly unusual for a consumer device to ship without RS232 and I could only say “yeah”
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 HDMI than a USB
Display port has a much more usable design, with a chamfer that is about twice the size as HDMI.
Hyperbole aside, there are some very good reasons to go with round connectors, it can be very strong and you can put a big nut on them to have an extremely secure lock. however the PS2 connector is nether of these things, It would require a much more robust key to work well.
The worst connector I ever encountered was on a old ATI capture card, it was the same barrel as a ps2 connector but had about 15 pins. Everything had to be perfect for it to insert, a tiny scratch or a slightly bent pin, it was not going anywhere.
The Apple desktop bus (ADB) that was used for keyboards and mice in Mac-land was also round. They improved it by using asymmetrical plugs, which marginally helped.
It's so bad it takes me 3 attempts to plug in USB-A blind, at least 50% of the time.
I've definitely cursed many times failing to plug in non-rectangular VGA, serial and parallel cables ;)
[edit: it is still better, but not a panacea]
https://ae01.alicdn.com/kf/HTB1XeKTDHSYBuNjSspiq6xNzpXae.jpg...
imgur mirror https://i.imgur.com/RQvMfhT.png
random newegg link: https://www.newegg.com/p/2MV-00MD-00DX3
Not really sure that that's USB's fault so much as a lack of front USB ports. I think in those cases the consumer can chose to get some sort of hub that's easier to access/can be pulled out from behind their setup.
Now that C exists though, idk if we really need to go much further. Connector much smaller than it is now will become fragile.
I've always thought they could add a single fiber core to USB cables for some "ultra high speed" standard, since USB4 is predicted to top out at 80GBps, but we could get 50Tbps or so over a single fiber if we really needed to.
But after owning several fiber cables, for networking and HDMI fiber based cables...yeah they're far, far too weak to replace copper. Just look at 'em wrong and they snap/break.
Plus tbf if we get 80gbps from usb4...the problem then becomes that we don't reaaaally have a use case for that speed. Maybe network adaptors, but beyond that...I mean a modern SSD will saturate that with a sequential read I suppose, but still.
1: GND
2: DATA +/-
3: VCC
4: DATA +/-
5: GNDEdit: see https://en.wikipedia.org/wiki/USB_communications#Signaling_s...
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
https://electronics.stackexchange.com/questions/73295/in-a-u...
It works for Ethernet because the transmit and receive lanes are separate, but with USB, there's only one pair used for both directions.
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.
I really really really hope that this was just an error by the journalist, and not Bhatt essentially lying to justify the choice.
There are of course various devices which somehow ended up using TRRS for USB, but unplugging/plugging those while powered is definitely not recommended:
https://www.reddit.com/r/ErgoMechKeyboards/comments/rt083u/a...
http://www.totekinternational.com/35mm-trrs-to-usb-a-male-ca...
https://pinoutguide.com/PortableDevices/ipod_shuffle_pinout....
1: GND/sense
2: DATA +/-
3: VCC
4: DATA +/-
5: GND/sense
The device will sense LO on 1 and HI on 5 if either both sides are plugged in straight or both sides are plugged in reversed, but it will sense HI on 1 and LO on 5 if exactly one of them is reversed. This allows the device to detect when inversion of D+/D- is needed.
Isn't that essentially what all ethernet cables do? it's not like this something never done before.
But yeah that was only one of many misdesigns along the way. Like making turning ports on and off optional features, mini-usb (seriously, none other usb version I've seen failed as often as mini-usb connectors), just how overcomplicated USB-PD is, or the recent mess in USB-C cabling.
Data lines -- use differential signalling and polarity determined by whether +/- got reversed by the rectifier or not.
Or do like Comcast does and put all bidirectional data through 1 conductor at multi-gigabit speeds.
> Or do like Comcast does and put all bidirectional data through 1 conductor at multi-gigabit speeds.
And how much modem's transceiver cost ? And how does that compare to cost of computer mouse or other cheap USB peripherals.
The usual implementation is using diodes, but that means you lose twice the diode forward voltage to the rectifier. Even with a Schottky diode that means you are losing 0.5V-1.0V. That's a 10%-20% loss at 5V!
You could use a transistor-based "ideal diode" solution, but that's not going to be cheap - especially in the 90s.
The shitty part of USB-A is that the tactile feedback of being slightly misaligned is identical to it being upside down. My experience tells me no amount of vigorous jiggling or extreme self-confidence will ever allow for consistent average 1.5 attempt plugins.
All the standards before USB were in my memory even less user-friendly — 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. Almost zero clearance from the plug case, that really did suck. Screw it in slightly loser next time, now you’ve got a flickering monitor, dummy.
And ps2/mini-din connectors sucked too - having the connector off-center or at the wrong rotation also felt quite indistinguishable.
The floating tongue of the USB connection is in the socket, not the on the cable. As in the most fragile part of the design is on the device side, not the cable side. This means that you can more easily break your $1000 device not the $2 cable. They repeated this mistake with USB-C as well.
It's not hard to make a port where the cable is the free floating tongue and the device is a more robust socket that wraps around that fragile piece. I know everyone's happy about the iPhone moving to USB-C but the tongue on the cable side that it had was much better. Anyone who's tripped on a cable and broken a USB socket can attest to this.
The cable is responsible for the grip. You do get a protruding tongue on the device side, but it's well protected.
Of course, there was no way to detect this by feel.
worst I ever had was the computer side falling out on the outside (no bolt, it was just threaded into the case itself)
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.)
- Loosely plug in the connector
- Screw in the right side, relatively tight
- Use the right screw as a pivot point, by pushing the plug to the left, this will properly seat in the connector
- Screw in the left side until it touches, do not tighten
To unscrew, use the left side as a pivot point by pushing the plug to the right, this should loosen the right screw, unscrew it, then, unscrew the left side, which shouldn't be tight if you did it correctly.
Note: you can switch left for right and right for left.
The general idea is to wiggle left and right by using the screws as pivots. Do this to unscrew if it is too tight. If only one side is screwed in (don't do that) and it is too tight, screw in the other side and use the pivot trick.
I don't like not screwing these in as they have a tendency to come loose, especially since they also have poor feedback and chances are that they aren't properly inserted to begin with.
And side note: another thing I hate with this plugs is that when you pull out the cable, the plug tends to grab ever other cable that's on their way. In fact, some of these plugs look suspiciously like boat anchors and seem to be just as effective at grabbing stuff.
Making the USB connectors symmetric in their outer shape but not symmetrically pluggable was really inexcusable. When it came out I remember thinking that it was worse than any of the existing connectors. And this is supposed to be the new “universal” connector?
I never personally had a problem with them, but I can attest that people did. At my first job (a small computer shop), we had multiple customers who tried to jam their D-sub connector on wrong, and broke one or more pins off. Since this was back in the day when the cable was hard wired into the monitor, that generally meant they had to buy a new monitor.
(Though, that keyboard and mouse were different ports was stupid, so it loses points there)
I can totally see how they were designed to theoretically allow for it; practically, the tactile feedback for the correct orientation is just way too subtle.
And regarding the two different ports: I can't remember (or rather, I was never motivated to revisit the plugs once connected to experiment, since it was such a pain) – was there a technical reason for that, or could modern mainboards/BIOSes/OSes detect and correct for that?
The only upside of PS/2 was a higher mouse data rate, particularly with high monitor refresh rates, made mouse movement smoother. You didn't get this for free in Windows though, you needed a registry tweak to tell the mouse driver to bump the sample rate.
The huge downside was that PS/2 peripherals couldn't be inserted when the PC is turned on. They need to be inserted at boot time, and aren't detected if they're plugged in later.
And the keyboard and mouse connectors were physically the same but not generally switchable.
That sounds silly, but I forgot a non-trivial number of times.
Yes, it was kind of annoying, but OTOH it provided reliable robustness. Today, many connectors are just too prone to unintentional disconnect. And in the case of optional locks, like e.g. on some DP cables, one never know if the cable has the lock or is just stuck.
I find it easy to use by feel alone. You can feel when the sleeve fits the socket. Then you can rotate it in the socket until it can go all the way in.
But… My old computers all had a slippery steel plate surrounding the jacks, and the jacks had plastic centers aligned flush with the plate, having the plug overlap the steel plate never felt terribly different from only having the rotation wrong.
Did that come out right?
(Asking as I have a similar hypothesis- depending on your answer.)
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'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.
An obviously key'd connector like firewire / ethernet would've solved all of USB-A's flip it thrice problems. And this could've been allowed in a backwards compatible where old USB-A cables were basically a skeleton key and the new USB-A cables had a ward that blocked them from fitting incorrectly.
[1]: https://electronics.stackexchange.com/questions/125011/how-d...
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 USB-C charging devices that will charge off of some cables, but not off the one that will charge my laptop. I now have a box of weird crappy cheap USB-C cables with taped-on notes that say which toys they'll charge.
I never had this problem with previous USBs. If the cable fit in the port, it would charge and transfer data. Sometimes you needed a different cable or port or something to go faster, but they all basically worked.
Number 1 absolutely has. I've been somewhat in the market for a tester that I can plug both ends of a USB-C cable into and see what voltage, speed, and other specs it supports since most of my cables have zero markings on them.
Kind of hilarious. It's the only example I've ever seen though so not a real problem IMO.
The cables issue is real, but I don't really see the alternative. Would everyone really be happier if all USB-C cables had to be expensive thick 40 Gb/s 100W cables? No.
(This is something Apple should fix at the software level by alerting the user, but it highlights the problem that cables are not readily distinguishable.)
https://daringfireball.net/linked/2023/10/05/farsace-iphone-...
At the beginning of USB-C you had devices that were not implementing the standard correctly, and using the wrong cable could fry a device.
Now the devices are better protected, you can charge any device with any charger. Of course the charger needs to be powerful enough but if it's too powerful it's still safe to use.
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.
Edit: in fact, trying now it seems to be perfectly recessed that I can't even push on it from an angle with the connector, it has to go straight in a bit before it even touches, on any of my devices
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%...
For people who are not versed in mechanical connector design it might look like the fragile part is that center wafer.
USB-A is massive compared to USB-C, that's why it's so robust, thick plastic, thick metal, wide connector lanes.
If USB-C is fragile, is just because it's so small, you can easily break it with not so much pressure.
But (2) seems very unlikely. Most consumers just won't even consider that it has an orientation, and after it fails a few times chuck it in the bin or send it back. If it comes with a device (i.e. printer or monitor comes with a non-reversible cable) they're likely to send the whole device back. That would be a ridiculous false economy for the manufacturer.
Connectors, cheap and reliable are hard to design, and there's that much solution that works, and economics of scale works wonderfully by this kind of mass production (the good enough converges to reliable cheap). Also, the backward compatibility is real, and not to be dismissed too lightly. Say, for an USB-A connector, would really go one way where a USB 3 cable and device should NOT work with your older computer ?
There will be waste, there will be disgruntlement, but at real diagnostic will be possible (instead of the vague indications like «use provided cable» we have for HDMI and DisplayPort). For power, you can already find cable with a mini LED display on the plug to show max wattage once plugged.
Limited cables will quickly have label to show their specific capability (4K/8K, for PD only, 100W 60W), for cables you buy. General case for cables provided by manufacturer is, you keep you cable with the device, no real confusion here.
I know many have the cable drawer full of just-in-case that never comes that would dream to have it blissfully replaced by unlabeled USB-C cables, but this is just not how general people handle the problem. They keep the cable with the device, and learn what they need before or after buying a replacement, or better, asking someone in a shop, those still exists for all I know.
For example, video-only cables are only possible if they have active electronics - so that means you are buying a very expensive cable which somehow doesn't follow the specs. I know Monoprice does make one, but it starts at $115 and it is explicitly marketed and labelled as video-only.
Low-voltage cables are the same thing. All passive cables can do 100W using 20V, and the 240W ones using 48V are explicitly marketed as such. There are some optical cables which do not transfer power at all, but again you're looking at specialized >$100 stuff. You don't just accidentally grab one of these out of your Box Of Cables.
As far as I am aware, no cable manufacturer cheaped out on the wiring because there is zero reason to. You can't simplify USB 2 cables like that, and anyone selling USB 3 cables wants all pins for it to actually be usable as a data cable.
The biggest problem with USB-C is that the USB Implementers Forum created a very clear design to indicate exactly what each device and cable is capable of - but then manufacturers decided it was ugly and just completely ignored it. If everyone just followed the damn spec there wouldn't be nearly as much confusion.
Yes you do. You set up the studio and wire it all up, with all of the devices, and with the right $100 wires and $30 wires and $2 wires. (Along with $50k in equipment.) But then you need to move out for some reason, so you tear it all down and it all gets boxed up and loaded into a truck and then you have nowhere to set that studio back up so then you end up with a box of cables in your living room that then gets shoved into your closet. Now you have a box of cables, some more expensive than others and you are just gonna randomly grab one until you find one with the right ends on but now also the right innards as well which means you'll have to test it.
I am not looking forwards to looking at a tangle of usb-c cables and extracting the one that actually meets my needs. Still better than trying to pull a DB9 through, but still.
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 the can down to 'let consumers figure it out' but there's hardly a realistic alternative, you just can't police ~10 billion cables sold a year across ~10 million retailers. I haven't heard of your first example anywhere actually happening, it sounds theoretical more than widespread in practice in 2023, 8 years into this USB-C thing.
As far as cables with different capabilities, what is the alternative here?
1. Physics of signaling demand certain capabilities require higher quality / more expensive cables. Zero chance you get people or manufacturers lined up around the idea of highest common denominator (e.g. 40gbps capable $30 cable when consumer wants a $3 charging cable), and that's sorta moot anyway because...
2. Standards evolve, and we're all tired of playing the game we've played for 50 years in tech of new physical connectors every few years.
It's either a) you have the same physical connector and different cables, or b) different physical connectors that briefly use the same cables before they become differentiated when standards evolve.
The reality is 'it works but not as good' (speed or charge-wise) is a superior tradeoff to 'I have to buy a totally different cable' in the high % of use cases where 'not as good' is possible, which is stuff like 'charge my phone' or 'plug my printer/audio device/whatever in'.
Honestly the only unforced errors I see with USB-C are consumer education related. USB versioning should be simple (3, 4, 5) not intentionally obtuse ("3.2 gen 2x2"), and something like iconography should be added to indicate premium cable capability (specific higher voltage & bandwidth capabilities) to avoid to play the plug in and try it game.
For a time at work, our desks had different docking stations for employees with Mac laptops or HP laptops. USB-C "standard" notwithstanding.
The set of permutations is too large to fit into an icon, but a lookup table allows for unlimited detail.
I've now had to replace 2 USB-C host ports (on expensive Apple devices, where an "official" repair would cost ~50% of the value of the device) despite taking reasonable care of my devices (under which care no other connectors ever failed).
Examining them under a magnifying glass showed that the metal pin delaminated from the plastic middle part of the host connector and was ever so slightly skewed towards the adjacent pin, presumably making enough contact/interference to make the whole thing fail.
In a sane design, a misalignment/skew of <1mm would be well within tolerance and would be a non-issue. Worse, despite the machine being from the same brand that ushered all this crap onto the world, there is no software support or notification to say that something is wrong - the machine just silently stopped charging after a random delay. Very annoying when you plug your machine in to charge and only realize (at the most inconvenient time) that it silently stopped charging and you've now drained whatever battery was remaining.
Even with the new ports, I can make it lose Thunderbolt/DisplayPort connection by bumping the connector. It's probably a mismatch of tolerances between connector and port (maybe my cables are out of spec), but it's never been a problem with any other connector.
From my understanding I think that is not technically possible because to pass video they need the data lines but maybe I'm mistaken?
IIUC again even if it did work I think these would be non-compliant. People hell-bent on doing non-compliant things would do it irrespective of any design.
> low-voltage only cables
That's a given due to physical constraints (length, diameter: would you accept that all cables are 0.8m / thick and unbendable). It was so with USB-A too, as well as non-standard power delivery, at the risk of setting things on fire or destroying devices. USB-PD makes it so that you basically can't fry anything or melt a cable, it falls back to the best possible through negotiation. But then again, people hell-bent on doing non-compliant things would do it irrespective of any design.
> 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.
Non-compliant for sure. Ah, yes, people hell-bent on doing non-compliant things would do it irrespective of any design.
At least with USB-C+USB-4+USB-PD we get a fighting chance.
> An obviously key'd connector like firewire / ethernet would've solved all of USB-A's flip it thrice problems
Rumour has it that USB-B which is keyed, has five positions due to squareness. FireWire and Ethernet have the same state superpositions as USB-A. Hell I've seen people shove an Ethernet cable the wrong way in and have it fit (breaking the infamous clip in the process). USB-C? I lay it basically flat and clip it in, barely looking at the connector and not even taking a glance at the port. Worst case it needs a few degrees rotation.
Counterexample: The Meta Quest link cables use a USB-C style connector but internally are very different from a regular cable.
It’s been around a long time and most people have managed just fine, and absolutely loved the common cable. And everyone hated the iPhone user because you had to pull out a new cable to charge it.
1. What speed does the cable support?
2. How much data does the cable support?
3. Can it support video over USB-C?
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.
It is kind of annoying that that functionality isn't built into phones and PCs though. There was some talk about building support into the Linux kernel[1] but it doesn't seem like that went anywhere.
[1]: https://people.kernel.org/bleung/now-how-many-usb-c-to-usb-c...
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.
The solution is - I guess - to buy plenty of 'good' multipurpose cables and throw anything that doesn't work as expected away.
regarding 1) look at this post from 2019: https://people.kernel.org/bleung/now-how-many-usb-c-to-usb-c... I imagine it only got worse in the mean time.
regarding 2) I have seen various posts in the past of devices that only work if the cables are connected in a specific orientation. Technical background is discussed here: https://acroname.com/blog/why-usb-c-connections-sometimes-do...
When USB-C was brand new, I got a flawed breakout board where only the socket's data pins on one side were connected. I did not notice it until it was soldered together and the device got power but no connection when the cable was connected in one orientation. But then I had already built a metal case to fit that breakout board perfectly, so I just left it in.
In my experience you can barely get the phones to survive without their "own" wall charger + cable combination. It's really terrible.
I don't understand how a 120€, 140W MacBook usb-c can't charge my OnePlus 8 at all. Not even with 5V 1A.
Whether or not this happens, it will have nothing to do with USB-C's merits as a connector. You could (theoretically) have the same mess happen with USB-A connectors as well.
USB 3 ? or 3x3 or 2x or ...with Thunderbolt or not...
Firewire only went in one way but it was never an issue because it's shape conveyed a clear orientation.
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
Sideways ports may be a crap shoot I'm not sure if their orientation is standardized. And I'm not sure about modern USB version if that's still the case of logo faces up.
Even now i do a small repair shop as a side business. Broken hdmi connectors because someone forced the connector in upside down isn’t exactly common but it’s not exactly rare either. Some people think stuff really needs to be forced together, apparently
Using electronics needs a drivers license like equivalent. Some people shouldn't have access to them if getting an HDMI connector wrong is an issue.
I bet everyone seriously wishes there were a "seriously honestly just not a fucking idiot" license. The fact that we know which way a connector goes puts us in a whole different league from the rest of the population; most people are so braindead stupid that they can't even fathom being smarter. Sometimes I wonder if being neurodivergent is even worth it. Do I even want the privilege of knowing enough of the bare minimum to outclass half the Earth, if it means that I'm constantly depressed by how stupid everyone else is?
BTW I wouldn't pass a graduation exam if my life depended on it, because my brain is not a textbook database of things that I don't care about. But that just means my ADHD has gotten the better of me.
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.
Which brings up the idea of not making it size compatible with the network port.
When I came back, I realized the Windows machine had a cheap Firewire socket that didn't enforce the orientation. I had plugged in my iPod upsidedown.
I don't remember what it fried. I don't remember the iPod dying, so I'm guessing that socket never worked again.
Some part of the design process here was managed very badly.
Technology Connections dig in to this in "Power outlets are topsy turvy - but does it matter?"
The rest of the video digs into the claimed benefits of turning them upside down, and finds that they're quite small and probably outweighed by the inconvenience of the sheer number of devices that assume that you're using the cute orientation.
Hopefully only with a hammer!?
This also doesn't explain why three-state and five-state also apply to resp. mini+micro USB-A and USB-B.
Oh wait, people don't look at the port front and center and fail to memorize the port direction, irrespective of shape, that's why.
I called this USBedazzling. The other folks in the office didn't think it was a funny as I did.
Or just bedazzle the port if it's wrong. I've only ever once encountered a backwards port. Cough HP cough
USB didn't show up in the O/S. Thought maybe it wasn't formatted correctly and went through some diagnostics. Eventually went for the remove it / plug it back in technique. Had a look at the back of the PC and noticed I'd managed to plug it into an empty Ethernet port.... yeah they're about the same width give or take some tolerance. Also usually placed right next to each other.
Back on topic, I do find those bare/exposed usb keys (like a yubikey) to be quite annoying.
I guess you trade one annoyance (how to plug them in) for another annoyance (too thick for a wallet/keychain).
USB 1 stayed plugged in, required no screws, had higher bandwidth than any data port you'd find on a typical PC, the wires were much thinner, and it could even power low power devices! Yes, a design that doesn't take three tries (my average) to get right would be nice, but it exceeded every existing port by miles. Audio jacks were the only ports that didn't have a direction back then.
The only exception I know of is that Apple Desktop Bus (mini-DIN) had been designed (by Woz !) to be supposed to be hot-pluggable but Apple cheaped out on overcurrent protection so it never was.
Edit: I forgot: in a MIDI connection there is an opto-coupler behind the receiving end, to electrically separate devices.
And I distinctly remember getting excited about upgrading to a motherboard that supported USB for the hot-pluggability. I was overexcited, but still.
On computers perhaps. There were plenty of round connectors in other uses though, e.g. Edison screw, Belling-Lee (TV/FM connectors), RCA, BNC, type C and type N RF, TOSLINK, etc.
Most of those wouldn't have been much use for a computer serial port though. Something like TOSLINK, with power and optic fibre would have been great. Too expensive at the time I think. But a round TRRP-style jack would have worked and been cheap.
Agree that USB-A was much better than the existing alternatives though.
And in fact USB-C is not really physically reversible, because the hardware detects which way it's plugged in and permutes the signals, as opposed to mirroring all the wires, so there is indeed a "right" way of inserting an USB-C plug, except it's impossible to tell which it is without a dedicated hardware tester.
For USB3/4 signals, yes. But the hardware needed to interact with those signals is complex enough that making it also support swapping pins is a minor detail.
The USB2 and power lines, on the other hand, are all present on both sides. This means that simple devices don't need to detect orientation; they can connect the duplicated pins together and everything works.
[1] https://www.microchip.com/en-us/application-notes/an1953, 1.3.1
Does that cause a noticable difference, for example lower speeds?
Once you get into the USB 4 range you're going to need all four lanes anyways, so you can just do the permutation in software.
But when I unplugged the cable and reversed it then the issue disappeared
https://text.npr.org/2019/06/21/734451600/ever-plugged-a-usb...
I once put one of the drives into my test system, and plugged in the power connector. It used a standard Molex connector [1].
The way the drive was mounted I couldn't actually see the plug or socket. It's a keyed connector so that should not be a problem. Yet somehow I managed to plug it in upside down which fried the drive.
Afterwards I did some tests and found that the plastic on the connector on the drive was very soft. If you tried to plug in the wrong way the parts that were supposed to get in the way due to the keying would just deform out of the weight.
It took more force to insert it the wrong way, but not more than was often needed when you happened across a plug and socket combination that were a tight fit so that didn't tip you off.
I reported that to the person who had loaned us the drive and he told me he'd fried two of them that way. He said that when he told IBM about that his contact there said that they were losing something like 10% of the drives during testing right after manufacturing due to their technicians getting it backward, and the parts list had already been revised to switch to a connector hard enough for the keying to actually work.
Hah, sounds like the editor is someone too young to have used serial/parallel/vga ports. Early business PCs, for what ever reason[1] were built like tanks. They weighed dozens of kgs/pounds. And the connectors were often screwed in with a screwdriver for good measure.
Yes, you could wing it when being sloppy, but they weren't always very tight and cables heavy so you'd want them screwed in for a long-term installation to avoid issues.
When USB came out it was a revelation that you just needed to pop it in and were done. Yes, you'd have to look at it first, but that was the same with every other port of before that. I remember PS/2 being perhaps hardest to line up correctly.
So USB 1.0 fixed one problem, but not every problem. Not exactly a reason to cry.
[1] Probably inertia from main/minicomputers which were serious installations and needed to keep running through wartime. :-/
Exactly what made USB so awesome when it first came out. I guess you had to be there.
I despise this "design decision." Literally bakes in the 50% of the time you plug it in the wrong orientation and lose seconds of your life. Who cares if the sands of time are moving more rapidly than asteroids? We can save money and make more of these badboys to fill the landfills with once they're obsolete. Hard to argue that logic that clearly won via market dynamics. But where are we now?
It was a nightmare. And virtually none of those ports would self-install drivers when a device was plugged into it. USB 1.0 was magic when it came out.
> Making USB reversible to begin with would have necessitated twice as many wires and twice as many circuits, and would have doubled the cost.
Adding more wires, even if it is a few is not the cheapest one and therefore not the one that wins. The relative convenience of a feature is always trumped in early days by cost-to-produce.
USB-C recently introducing the symmetry of the connector does not imply that manufacturers will use it... ie you have a symmetric connector that performs differently based on how it was plugged.
They overlooked the statistically significant case where it takes more than two tries to plug it in correctly. Knowing you might have been wrong makes you prematurely abandon an attempt where you had it set the right way.
Of course the vertical ports behind a machine are a bit harder to access, but... well anyway they are. And usually those are not the ones I unplug/replug often.
The spec almost requires manufacturers to do that. https://fabiensanglard.net/usbcheat/usb1.1.pdf, page 81:
“The usb icon is embossed, in a recessed area, on the topside of the USB plug”
“Receptacles should be oriented to allow the Icon on the plug to be visible during the mating process”
So, there must be a tactile and visual indicator (the recessed usb icon) and it should be visible.
They didn’t say “clearly visible”, though.
But I guess it might just have two wires (+5V and ground) and no data wires (I can't check it now because I'm at work).
USB Type-A has longer contacts for pins 1 and 4, the power pins, so they contact first and remain contacted before the data pins make contact. You can see that in this picture https://www.electroschematics.com/usb-how-things-work/.
Now consider the forward-looking bandwidth implications with that class of physical interconnect.
I learned this the hard way - turns out your computer will just suddenly hard power off when you try to do this.
Despite the obvious design drawback, I can't blame intel entirely, a big contributor to the problem was that the ports were still being positioned in hard to access areas by computer makers. The first iMac design was a bit more forward thinking in this regard, whereby USB ports were prominently positioned on either side of the keyboard, this made it very easy to plug in the USB mouse and use the other for something like a USB stick. The problem with the type A design isn't just the orientation issue, the rectangular port design provides very little tolerance for off-angle insertion, having the port in full view helped a lot with insertion.
Not really. I've got a cable which is USB 2.0 type A one side, Micro-B the other side and both the sides are perfectly reversible. It's already been many years since I've bought it and it still serves me reliably for both charging and data needs. The manufacturer didn't even have to change the standard to produce a reversible cable working great with all the old devices whose manufacturers never heard reversible USB cables exist.
USB is by far the worst designed thing in the history of humankind, in terms of the cumulative amount of frustration it has caused globally.
All common-sense usability principles were ignored, and these are not new principles. Take the old RS-232C or RJ45 jacks, you just looked at it and you knew which way to plug it in. Hell you could do it blindfolded by feel.
All he had to do was make one side of the connector rounded. But still a vast improvement.
Turns out that plugging in USB-A cables is a skill you can learn in 5 seconds.
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."
Um, no? The iMac had an Ethernet port, a phone jack for an internal modem, and TWO FIREWIRE PORTS. And Microphone and Speaker jacks.
No, this really only increases your frustration once you find out that some USB manufacturers can't tell their head from their *** when it comes to making the connector.
ASUS, I'm looking at you.
Radially symmetric, it can go in any direction. I've heard arguments this could cause connection issues since it could rotate while connected, causing small contact misses, but I think that could be designed around.
The bus and tag connector: https://en.wikipedia.org/wiki/Bus_and_Tag
The cost of zillions of the same panel mount connector will converge to dirt cheap. Although cents matter, user experience matters more if everyone hates your craptastic cheap design. Thankfully, Apple came along and gave the world USB-C which simply increased the bandwidth and current with the convenience of rotational symmetry. A USB-C panel-mount connector costs $0.492 in bulk. Fancy rugged and waterproof ones are $2.18. Micro USB B costs $0.45 in bulk. 10% increase in cost: big whoop for everything except Arduinos and portable kids' night lights.
'Okay, but: why wasn’t the plug reversible?
Ajay Bhatt: Good question. We had looked at it, but the whole goal here was to make it very inexpensive, and at that point, we were trying to solve all the USB problems with two wires. At that point, if you added wires to make things flippable, you have to add wires, and you also have to add a lot of silicon. Wires and pins cost real money, so we decided to keep it as cheap as possible. With serial port and parallel port, there were versions that were 25 pins and 36 pins and so on and so forth. The cables were very thick and expensive. We were trying to solve all the problems. We went in favor of fewer wires. In hindsight, a flippable connector would have been better.
Our goal was to say that this interface should be such that it should work on a mouse and it should also work on a high-end printer or on digital cameras. That’s what we were looking at, the range of products. At one end, we wanted it simple enough, so there could be very low costs. At the other end, we wanted to make sure that it could be scaled and, just as we speak today, we’re running the USB at tens of gigs. The original one was running at 12 megs. We’ve come a long way in scaling.'
[1] of course USB isn't always truly differential which is part of the problem.
The guy has been responsible for unbelievable amounts of human aggravation.
I would argue that what USB (1.1-2.0) does differently from previous serial peripheral ports is mostly software and standardization, and really relate to making it cheap and simple for "normal people" to use:
1. USB 1.1 supports only two bit rates (1.5 and 12 Mbps), which is autoconfigured before device enumeration. 12 = 8 * 1.5, so the clock divider is cheap and easy.
2. USB limits cables to fairly short lengths (<=5m) compared to earlier serial ports (RS-422 supports 10 Mbps at 15m)
3. USB (pre-OTG extensions) rigorously enforced the idea of a "host" (upstream) and "device" (downstream), at both the protocol and physical connector level (which greatly simplifies things--for example, you can't create a loop, and don't need STP to detect it). A child can easily see that a B (device) socket doesn't fit an A (host) plug.
4. USB device enumeration and configuration are extensively software based, and USB defines a number of standard device classes so that many common types of devices (e.g., keyboards, mice) don't need specific drivers.
5. One thing that USB does that's less common among serial peripheral interfaces is to use a single differential pair for data going in both directions (it's time-shared: so the host polls the device then the device responds). The pin-count is less than a "regular" RS-422 port, but you still get the advantages of differential signaling.
6. USB carries power with only one more pin than needed to create a minimal bidirectional serial data connection, so "lite" devices don't need a separate power connector (ignoring very slow protocols like "1-wire").
7. USB does some funny things with packet framing (like NRZI encoding and bit-stuffing) and some things to help reduce device cost (like the JKJKJK packet preamble to sync the device baud-rate generator and using SE1/SE0 states for device disconnect and bus reset signaling), but none of that is really fundamental to making a 10Mbps-class serial interface.
USB-A has only 4 wires: they could have easily used a co-axial connector. Hell, they could have used a 3.5 mm TRRS phono cable and it would have been better.
Why do we put up with this shit?
Seriosly? Overcomplicated protocol to make it very hard to bit-bang and thus pay USB-IF for every chip, every logo. There was already 100mbit Ethernet at that time, just add power wires and use existing network stack in software, but how can you squish money from it?! Ofc they needed something new proprietary, overcomplicated, with terrible reliability. USB is the curse of modern hardware.
Honestly when this is the biggest problem you face on a daily basis, your life must be relatively easy.
1. Doesn't easily insert so assume I've got it upside down. Flip. 2. Still doesn't easily insert so inspect, and realize it had it right the first time. 3. Insert for real this time.
I don't miss usb-a, but it was a vast improvement over the rs-232 and parallel port cables that preceded it.
So on the rare occasion that you get it right by feel the first try, you’re not actually plugged in to anything and get to spend 10 minutes debugging your printer before noticing.
Wish I'd thought of this 15 years ago...
The number of times I've flipped it around more than once to get it right is absurd.
It must look hilarious if you zoomed out to population scale. Thousands of people flipping around USBs at any given second.
(Additional fun fact: the box says it uses Micro-USB.)
This man was ideal for the job of USB inventor.
Actually, I just made that up, but it seems kind of plausible.
my ILEC camera, PS5 game controller, iPhone, laptop, work laptop donglebook, all charge from the same cord and power block when they need to
my portable speaker is still microusb on one side and usb 2.0 or whatever nomenclature on the other side
airpods are primarily inductive charging, but it has a lightning cable port, along with my apple keyboard and mouse when I need to connect them to a different computer and go wireless again
I love how they write „in theory“
What a stupid thing to ignore.
Is this still true with USB-C?
There is only one more wire in a USB-C 2.0 cable: it is used to signal orientation and if an end is a power source, sink or a headphone adaptor.
USB-3 signals are more complicated though. There can be up to two bidirectional high-speed channels. The aforementioned sensing pin is used to figure out if those channels need to be swapped or not.
That turned out to be an over-estimate.