This cable should have never existed.



  • Seriously, this is not kosher USB. You could seriously mess up your stuff with it.

    I don't remember what piece of hardware it came with. It was here before I was.



  • What am I missing here?  It's a USB cable with two male ends.



  • @belgariontheking said:

    What am I missing here?  It's a USB cable with two male ends.
     

    Two male ends are an abomination, so sayeth the Lord in Leviticus.



  • @USB-IF said:

    Q6: You mean I can't make a direct cable connection like a null modem?

    A6: Correct. In fact, if you try this with an illegal A to A USB cable, you'll short the two PCs' power supplies together, possibly destroying one or both machines or causing a fire hazard. Even there were no danger to the machines from the problem with two power supplies, there still wouldn't be any way to get the two PCs talking to each other, since USB doesn't support that particular kind of communication.



  •  Many monitors have A USB ports.



  • @dhromed said:

     Many monitors have A USB ports.

    That would explain the old one of these lying around our office. I went wtf when I saw it.



  • @Nyquist said:

    @dhromed said:

     Many monitors have A USB ports.

    That would explain the old one of these lying around our office. I went wtf when I saw it.


    Other devices can take A-A USB cables, but I've yet to find one, supposedly hubs and printers are common culprits.



  • "Dual power" Willem EPROM programmers use a USB A socket for [url=http://benryves.com/images/willem/willem_pcb3_small.jpg]power[/url] (and power only, programming is performed using the parallel port).



  • TRWTF is that someone actually has suggested that plugging a double-male cable into two machines will create some form of time paradox that destroys the face of the world (or at least their power supplies)
    The problem is that people dont understand USB. They think its like the old Parallel stuff still. USB runs at 5v@100mA. Not even enough to tingle your tongue. Last I remember, in order to make the diodes that are used in the bridges in most modern USB systems (so that the occasional +5/-5 hiccup gets handled) is somewhere around 5v@200-400A (note, the mA/A distinction), and a sane (see: FCC certified) USB host is going to be doing MUCH less than that.

    Why are people so dense?



  •  @Indrora said:

    TRWTF is that someone actually has suggested that plugging a double-male cable into two machines will create some form of time paradox that destroys the face of the world (or at least their power supplies)
    The problem is that people dont understand USB. They think its like the old Parallel stuff still. USB runs at 5v@100mA. Not even enough to tingle your tongue. Last I remember, in order to make the diodes that are used in the bridges in most modern USB systems (so that the occasional +5/-5 hiccup gets handled) is somewhere around 5v@200-400A (note, the mA/A distinction), and a sane (see: FCC certified) USB host is going to be doing MUCH less than that.

    Why are people so dense?

    because they're made of depleted uranium?



  •  I get it, not kosher because it's not circumcised! L'Chaim!



  • @dhromed said:

     Many monitors have A USB ports.

     

    Seems strange/unwise (because of the problems you get when you present them to common users). I'd think they would have B ports like all hubs I've know (since I wouldn't know any other reason for a monitor to have a USB connection, other than maybe a card reader)



  •  the problem is, not that it will connect the two 5v supplies, which are over-voltage and over-current protected, but that it will connect the two chassis earths. Most USB ports are soldered fairly solidly to the earths. The earths of two mains-connected systems are often at a different potential, often by a considerable amount. Research "Ground loops" for more info.

    Like power leads with two plugs, this item is a bad idea. Not quite as dangerous, however.  Mind you, the most likely result of connecting it to two systems is likely to be just "it doesn't work", but it could crash the system, and damage is definitely possible.

     



  • @morbiuswilters said:

    @belgariontheking said:

    What am I missing here?  It's a USB cable with two male ends.
     

    Two male ends are an abomination, so sayeth the Lord in Leviticus.

     Those two girls in that video I just saw didn't seem to mind... uhm, I mean, nevermind shifty eyes


  • Discourse touched me in a no-no place

    @dtech said:

    (since I wouldn't know any other reason for a monitor to have a USB connection, other than maybe a card reader)
    I've seen monitors with USB hubs in them; i.e. they have more than one A recepticle. Presumably as some sort of cable tidy/extension to plug keyboards and mice into.

    Here's one.

    The cables for that monitor would suggest (but it's not clear in that picture) that the PC/Monitor connector is an USB-A plug/plug one. Which raises the question, how should you connect two such USB hubs together with a cable if you're not supposed to use the one supplied? (I'd probably naively suggest a USB-A/USB-B cable, but I'm sure there's a (technical) reason for not doing so.)



  • @PJH said:

    @dtech said:

    (since I wouldn't know any other reason for a monitor to have a USB connection, other than maybe a card reader)
    I've seen monitors with USB hubs in them; i.e. they have more than one A recepticle. Presumably as some sort of cable tidy/extension to plug keyboards and mice into.

    Here's one.

    The cables for that monitor would suggest (but it's not clear in that picture) that the PC/Monitor connector is an USB-A plug/plug one. Which raises the question, how should you connect two such USB hubs together with a cable if you're not supposed to use the one supplied? (I'd probably naively suggest a USB-A/USB-B cable, but I'm sure there's a (technical) reason for not doing so.)

    I got the impression that having a USB hub was one of the sensible reasons dtech could figure out for a monitor to have a USB connection (the other being the card reader). The USB cable in your cable picture looks to me like a standard A-B cable (look closely at the width of the obscured connector). The uplink port on the monitor is likely on the bottom edge along with video and power connectors.



  • @Indrora said:

    TRWTF is that someone actually has suggested that plugging a double-male cable into two machines will create some form of time paradox that destroys the face of the world (or at least their power supplies)
    The problem is that people dont understand USB. They think its like the old Parallel stuff still. USB runs at 5v@100mA. Not even enough to tingle your tongue. Last I remember, in order to make the diodes that are used in the bridges in most modern USB systems (so that the occasional +5/-5 hiccup gets handled) is somewhere around 5v@200-400A (note, the mA/A distinction), and a sane (see: FCC certified) USB host is going to be doing MUCH less than that.

    Why are people so dense?

    Not all USB ports are properly protected. Some cheaper mobos just connect the 5v from the PSU directly to the USB port. If you manage to jam in an USB device the wrong way around (bottom up) then you short the 5V with the ground. It takes some effort, but people are stupid enough to do it, trust me. Same with the A-A USB cables.



  • @dtech said:

    @dhromed said:

     Many monitors have A USB ports.

     

    Seems strange/unwise (because of the problems you get when you present them to common users). I'd think they would have B ports like all hubs I've know (since I wouldn't know any other reason for a monitor to have a USB connection, other than maybe a card reader)

     

    You may feel that way, but it doesn't change reality. A connectors are very commonly found on monitors, and I have never seen a monitor with a B receptable [pixation needed].

    I suppose an USB connector on your monitor is nearer at hand than the ones on the front of your case, but since you need an extra cable, the benefit is dubious.

    The
    saner option, if perhaps not the cheaper one, would be for monitors to
    contain 1 B receptacle, so you can have a proper AB cable to the
    computer.

     



  • @Daid said:

    people are stupid enough to do it
     

    I've heard about people jamming LPT in the wrong way, so nothing surprises me.



  • @robbak said:

     the problem is, not that it will connect the two 5v supplies, which are over-voltage and over-current protected, but that it will connect the two chassis earths. Most USB ports are soldered fairly solidly to the earths. The earths of two mains-connected systems are often at a different potential, often by a considerable amount. Research "Ground loops" for more info.

    Like power leads with two plugs, this item is a bad idea. Not quite as dangerous, however.  Mind you, the most likely result of connecting it to two systems is likely to be just "it doesn't work", but it could crash the system, and damage is definitely possible.

    That cable is a few feet long.  How is a significant difference in ground potential going to exist between two machines a few feet apart?  I know it could happen, but it seems fairly unlikely they wouldn't share a common ground.  Also, the same argument would seem to apply to any regular B-connector USB equipment that is grounded.



  • @dhromed said:

    You may feel that way, but it doesn't change reality. A connectors are very commonly found on monitors, and I have never seen a monitor with a B receptable [pixation needed].

     

    That's a Dell one, so a proper B socket might not be that unusual.



  • My last HDD enclosure used one of these cables. I had to go back because I hadn't bothered with buying a cable - teach me to think something confirms to a standard.



  • @hallo.amt said:

    [pic of B ] That's a Dell one, so a proper B socket might not be that unusual.
     

    Aight.

    All our monitors are Dell as well, but contain no B's.



  • @dhromed said:

    You may feel that way, but it doesn't change reality. A connectors are very commonly found on monitors, and I have never seen a monitor with a B receptable [pixation needed].

    What. I've never seen a monitor or other hub or device that has a normal-size A port for uplink. Mobile devices that can act as both device and host are a bit of a special case, but those usually have mini/micro ports. I've heard of those standards-violating A-A cables before, maybe even seen one somewhere, but certainly not in any equipment I've used.



  • @dhromed said:

    @hallo.amt said:

    [pic of B ] That's a Dell one, so a proper B socket might not be that unusual.
     

    Aight.

    All our monitors are Dell as well, but contain no B's.

     

    Further evidence of the ongoing gender confusion in Dutchland.

    I have one of those Dell monitors and it has a B uplink port.  And so does every other monitor I've ever seen with an integrated USB hub and/or card reader.



  • And its not a really big WTF. I have a USB cable with 3 male ends. its for a portable HDD. Two of the heads are plugged into the PC side and the other remaining one is applied to the proper device.



  • @Indrora said:

    I have a USB cable with 3 male ends. its for a portable HDD. Two of the heads are plugged into the PC side and the other remaining one is applied to the proper device.
    What would be the benefit of this?  Do they think they can get faster reads and writes if they take up two USB ports on the PC?  More importantly, can they?


  • Discourse touched me in a no-no place

    @belgariontheking said:

    @Indrora said:

    I have a USB cable with 3 male ends. its for a portable HDD. Two of the heads are plugged into the PC side and the other remaining one is applied to the proper device.
    What would be the benefit of this?  Do they think they can get faster reads and writes if they take up two USB ports on the PC?  More importantly, can they?

    It's for if the drive needs more current to run, nothing to do with data speeds.



  • @belgariontheking said:

    @Indrora said:

    I have a USB cable with 3 male ends. its for a portable HDD. Two of the heads are plugged into the PC side and the other remaining one is applied to the proper device.
    What would be the benefit of this?  Do they think they can get faster reads and writes if they take up two USB ports on the PC?  More importantly, can they?

     

    Separating power and data, perhaps? Of course, if that were the case you'd think there'd be two at each end.



  • @PJH said:

    @belgariontheking said:
    @Indrora said:
    I have a USB cable with 3 male ends. its for a portable HDD. Two of the heads are plugged into the PC side and the other remaining one is applied to the proper device
    What would be the benefit of this?  Do they think they can get faster reads and writes if they take up two USB ports on the PC?  More importantly, can they?
    It's for if the drive needs more current to run, nothing to do with data speeds.
    Ahh, that makes sense.  I've only seen ones that have a single USB and if they need more power, they plug into the wall.



  • @belgariontheking said:

    @PJH said:

    @belgariontheking said:
    @Indrora said:
    I have a USB cable with 3 male ends. its for a portable HDD. Two of the heads are plugged into the PC side and the other remaining one is applied to the proper device
    What would be the benefit of this?  Do they think they can get faster reads and writes if they take up two USB ports on the PC?  More importantly, can they?
    It's for if the drive needs more current to run, nothing to do with data speeds.
    Ahh, that makes sense.  I've only seen ones that have a single USB and if they need more power, they plug into the wall.

    For the record I have one cable like that too. The second PC plug actually lets you plug another A cable into it, since it's only for power, meaning it effectively only uses up one port.



  • @Anonymouse said:

    @morbiuswilters said:

    @belgariontheking said:

    What am I missing here?  It's a USB cable with two male ends.
     

    Two male ends are an abomination, so sayeth the Lord in Leviticus.

     Those two girls in that video I just saw didn't seem to mind... uhm, I mean, nevermind *shifty eyes*

    Two usb-a one cup?


  • Now, TRWTF is that people think that when you plug a USB hub port to a USB hub port, it'll explode. THE USB STANDARD HANDLES THIS PEOPLE. The standard says that if the device sends the "Host" dance before the 'host' has started, its either OTG (which should be handled appropriately) or to completely fucking ignore it!
    I've measured the voltages on a USB line -- the only thing thats "grounded" is the outer sheilding. Thats its point. Do I need to refresh some memory that the wiring standard is
    .----. SHEILD
    1: Black, -5V
    2: Green, Data + (or - I cant remember)
    3: White, Data - ( ``` )
    4: Red, +5V
    ---- SHEILD
    The standard layout for USB is as follows (Assuming a "To Spec Error Handling System", though we know that is complete shit):

    1------>|-------(Hub +5)
    2------|<-------(Hub TX)
    3------>|-------(Hub RX)
    4------|<-------(Hub -5)


    But still, you're not going to blow your fucking power supply doing shit like that. IN FACT, USB3, OTG specifies that a cable like this is Perfectly Valid. So stop whining.


  • OH GOD, KILL IT BEFORE IT GETS TO THE CHILDREN.


    Unholy Hellbeast



  • My laptop died not too long ago; I purchased an enclosure for the hard drive, so that I could continue to access the data on it.  This is the cable that came with said enclosure.  I'm guessing you could connect two hard drives via the same USB cable?  Not 100% sure what that third terminator is for...




  • I use a cable like this to communicate back to the computer I'm working on. It helps with things like saving files to a disk and then reading them off the disk.


  • Discourse touched me in a no-no place

    @Jayman said:

    My laptop died not too long ago; I purchased an enclosure for the hard drive, so that I could continue to access the data on it.  This is the cable that came with said enclosure.  I'm guessing you could connect two hard drives via the same USB cable?  Not 100% sure what that third terminator is for...

    I don't think you should be using that cable.



  • @PJH said:

    @Jayman said:

    My laptop died not too long ago; I purchased an enclosure for the hard drive, so that I could continue to access the data on it.  This is the cable that came with said enclosure.  I'm guessing you could connect two hard drives via the same USB cable?  Not 100% sure what that third terminator is for...

    I don't think you should be using that cable.
     

     

    Why?  Because I have no need or desire to know exactly what the functionality is of the unneeded extra equipment provided?  If I needed to completely understand every bit of technology I ever use, I wouldn't be driving.  I basically know what a lot of the components in the engine are doing (I know enough to replace alternators, transmissions, and other basic maintenance), but I don't know (for example) exactly what the mass airflow sensor does.  Does that mean I shouldn't use my vehicle?

     

    This cable was provided, and works fine.  I have no intentions of ever using the third USB connector, so I ignore it.



  • @Jayman said:

    I don't know (for example) exactly what the mass airflow sensor does.  Does that mean I shouldn't use my vehicle?

     

    Umm... It senses the mass of the air flowing into the engine.


  • Discourse touched me in a no-no place

    @Jayman said:

    Why?  Because I have no need or desire to know exactly what the functionality is of the unneeded extra equipment provided? 

    Um, Yes. This is a problem? In this context, aren't you acting like (I presume) one of the people you support in other areas?

    It shouldn't have been provided to begin with, but since you have the knowledge (or serendipiity to come across this thread and realise it aplies to you) to know there's a problem with it, but you don't know what it might be....

    Yes. You shouldn't use it. If you don't know why, but suspect you shouldn't (because of this) why would you?

    You clearly haven't read the other posts in the thread to realise the problems for such things, or potentially why they exist.



  • @dhromed said:

    @hallo.amt said:

    [pic of B ] That's a Dell one, so a proper B socket might not be that unusual.
     

    Aight.

    All our monitors are Dell as well, but contain no B's.

     

    Stupid question: they do contain USB ports? Because if they do, what is the connection they have, A ports for uplink?



  • @dtech said:

    Stupid question: they do contain USB ports? Because if they do, what is the connection they have, A ports for uplink?
     

    It's exactly the same as PJH's link further up. Two A receptables on the side. It's a common sight and I've never seen anything else, save for zero ports on cheaper models.



  •  @Jayman said:

    My laptop died not too long ago; I purchased an enclosure for the hard drive, so that I could continue to access the data on it.  This is the cable that came with said enclosure.  I'm guessing you could connect two hard drives via the same USB cable?  Not 100% sure what that third terminator is for...

     

    I think you're actually supposed to plug both ends in the computer and the one connector to the drive, so that if the external drive needs more than 0.5A of power, it has it. Maybe one of the connectors don't have the data wires connected.

    Or it might just be sent on purpose so that people burn up their enclosures and void the warranty, and buy a second enclosure.

    Either way it's a dumb idea.



  •  A fun thing for try with your USB host device: try to fit an USB-A connector the other way round (as mentioned above) or short pin 1 and 4. This should give you a nice outlook on how your host system responds to bogus wiring. I've seen various tactics: emergency PSU shutdown, MB-controlled USB bus shutdown (on modern mobos this works really well), spontaneous system reset or no protection at all (molten plastic and magic smoke FTW!)

     I actually managed to do this myself several times by accident - I had (I have? gotta check) a damaged USB extension cord that used springs instead of a stiff pad to keep pins in place when the connector is attached to a socket. You had to think twice before inserting a pendrive - I made the mistake several times.

    DISCLAIMER: Those experiments are definately fun, but you may fry your favorite computer, despite whatever the manufacturer told you.



  • I've seen OP's cable for a really cheap 2-mode digital camera (takes really bad-looking 640x480 photos, can also act as a REALLY bad webcam). The camera has an A socket on it.

    Anyone know WTF db2's cable (A-to-2-A)might be for??



  • There are devices that have A sockets on them that require more power than normal USB. So the solution is to take up 2 usb slots.


  • Discourse touched me in a no-no place

     This is one of the annoying things about USB. There's no port support for dual-mode devices. For instance, my phone can act both as a USB device and a USB host, but I need to pay through the nose for special devices that are expecting the host to be a mini-B end (or hack a cable, as I have done). I've seen A/A cables before, and they almost always come with a device that normally acts as a standalone host, but can be set to device mode for some reason. Fortunately it doesn't happen much with consumer equipment. The B/B scenario is much more common in actual practice because most USB peripherals have only limited reason to be a host, but nobody makes cables for it because building peripherals expecting a B-ported host is much more lucrative (See: USB receivers for PDAs - $90+ vs. $15 for the same damned thing with an A-host cable)



  • @dhromed said:

    It's exactly the same as PJH's link further up. Two A receptables on the side. It's a common sight and I've never seen anything else, save for zero ports on cheaper models.
    Most Dells I've seen have 2 A ports on the side and 2 A ports on the bottom (next to all inputs, including an USB B port). On Samsungs I've seen 2 A and 1 B port on the side.



  • @ender said:

    Most Dells I've seen have 2 A ports on the side and 2 A ports on the bottom (next to all inputs, including an USB B port).
     

     checks

    Hey look at that, it's another set of A's, and one B.

     The world makes a little more sense now.


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