Keyboard connection workaround



  • Just came across this Geekhack topic – the following Heath Robinson approach is necessary to get certain mechanical keyboards to work on a Macintosh:

    Mac connected to USB to PS/2 adapter connected to PS/2 to USB adapter connected to USB keyboard

    Sometimes, daisy-chained adapters are needed: I have a vintage ALPS clicky keyboard connected using PC/AT → PS/2 then PS/2 → USB.

    But what sort of mental midget does it take to create a USB implementation that doesn't register on a Mac? <iCab>What is this?! We have standards, you know!</iCab>

    <font size="1"> +0.25 Internets for anyone who actually remembers that</font>



  • From your picture there appears to be two USB cords connected into two connectors, the pruprle one is obviously a USB-> PS/2, the other one appears to be a PS/2 female -> USB.

    I do not see any PC/AT plugs, which are 1/2" DIN plugs, in the picture at all.

    What is pictured appears to be non-functional, or at the very least non-standard; a USB A <-> USB A Cable does not conform to any known USB standard!



  • Wut? That's not my computer. The only reason it's on my website is to avoid overloading their server – in fact it's been down most of the evening from overload.

    The purple thing tells a compliant USB keyboard to drop down to PS/2 signalling. The blue cube is an active PS/2 to USB adapter.

    Basically the keyboard won't work on a Mac, but its controller IC supports PS/2 signalling, so that arrangement takes the keyboard down to PS/2 and then creates a new USB stream from it for the Macintosh. Its a complete absurdity borne of the inability to make one USB device talk to another, which is just inexcusable.

    The cable between the Mac and the blue cube is just an extension lead, possibly because the blue cube is a fat lummox. I've got one attached to my PC right now and it blocks the other front USB port.



  • One other thing … I have seen a Lenovo external hard drive with two female USB A sockets on it (plus Ethernet). And male A to male A leads do exist. Neither of the USB ports was labelled, so one can only presume that they're both universal upstream/downstream and you just jam your male A to male A into either one (unless it's a USB hub that runs off Ethernet) but who knows. Whatever it was it didn't make any sense.



  • @Daniel Beardsmore said:

    Wut? That's not my computer. The only reason it's on my website is to avoid overloading their server – in fact it's been down most of the evening from overload.

    He's not saying it's your computer, he's saying your description in the photo caption doesn't match the photo.

    I had the same confusion until I realized the line directly below the photo had nothing to do with the photo and was in fact you describing a completely different, non-pictured, setup. But it took me two read-throughs.

    In any case, where does the other end of the right-most cable go? Into the back of the PC? Because... as Esoterik says, a USB A -> USB A cable makes no sense, is part of no standard, and not available anywhere. Unless you build your own, I guess.



  • @blakeyrat said:

    @Daniel Beardsmore said:
    Wut? That's not my computer. The only reason it's on my website is to avoid overloading their server – in fact it's been down most of the evening from overload.

    He's not saying it's your computer, he's saying your description in the photo caption doesn't match the photo.

    I had the same confusion until I realized the line directly below the photo had nothing to do with the photo and was in fact you describing a completely different, non-pictured, setup. But it took me two read-throughs.

    In any case, where does the other end of the right-most cable go? Into the back of the PC? Because... as Esoterik says, a USB A -> USB A cable makes no sense, is part of no standard, and not available anywhere. Unless you build your own, I guess.

    They may be non-standard, but they certainly exist. Where I am we get a lot of cheap Chinese crap, and I have bought a number of el-cheapo external drive chassis with exactly this cable.

    In fact, I remember a discussion on this very forum about how they were dangerous because if you used them to connect one PC to another (HERP-DERP), any significant difference in the earth potentials between the two PCs could start releasing the magic smoke.



  • @Daniel Beardsmore said:

    One other thing … I have seen a Lenovo external hard drive with two female USB A sockets on it (plus Ethernet). And male A to male A leads do exist. Neither of the USB ports was labelled, so one can only presume that they're both universal upstream/downstream and you just jam your male A to male A into either one (unless it's a USB hub that runs off Ethernet) but who knows. Whatever it was it didn't make any sense.

    I wonder what would happen if you connected both of those sockets to two different ports on the same computer.



  • @Daniel Beardsmore said:

    Wut? That's not my computer. The only reason it's on my website is to avoid overloading their server – in fact it's been down most of the evening from overload.

    Wut? As others have said, it's your picture - the one you posted. Nobody said it was your computer.

    @Daniel Beardsmore said:

    The purple thing tells a compliant USB keyboard to drop down to PS/2 signalling. The blue cube is an active PS/2 to USB adapter.

    So no PC/AT is actually involved, then.

    @Daniel Beardsmore said:

    Its a complete absurdity borne of the inability to make one USB device talk to another, which is just inexcusable.

    Agreed, T actual WTF, etc. Perhaps Jobs decided the Apple universe differs from the PC universe.

    @Daniel Beardsmore said:

    The cable between the Mac and the blue cube is just an extension lead, possibly because the blue cube is a fat lummox. I've got one attached to my PC right now and it blocks the other front USB port.

    How? I'm presuming the blue cube doesn't plug into a USB port, it looks designed to go on the end of a USB plug - in which case, move it to one side.



  • @Cassidy said:

    Perhaps Jobs decided the Apple universe differs from the PC universe.

    Given that it's a particular keyboard that doesn't work, it's more likely to be the keyboard manufacturer's fault. Unless, of course, you happen to be an Apple-basher ;)

    But I also don't understand how this is supposed to work … I get how it all fits together, but the best I can make of it is that a designer somewhere didn't read the USB specs properly and put a USB-A jack into the purple cube, when it should have been fitted with a USB-B one, meaning you have to use a cable with two USB-A plugs to connect the cube to a computer.


  • Discourse touched me in a no-no place

    @Daniel Beardsmore said:

    And male A to male A leads do exist.
    Indeed. And they were called an abomination last time.



  • @Gurth said:

    Unless, of course, you happen to be an Apple-basher ;)

    Nope - not used enough "white goods" to bash them, and don't consider myself in a suitable position to Apple-bash.

    @Gurth said:

    But I also don't understand how this is supposed to work … I get how it all fits together, but the best I can make of it is that a designer somewhere didn't read the USB specs properly and put a USB-A jack into the purple cube, when it should have been fitted with a USB-B one, meaning you have to use a cable with two USB-A plugs to connect the cube to a computer.

    Okay, I fail at picture scrutinisation.... it looked to me like a USB-A plug (male) that went into the purple's socket (oo-er), rather than the purple bit having the USB-A plug connected to the USB extension cable.

    Seems not:


    @blakeyrat said:

    In any case, where does the other end of the right-most cable go? Into the back of the PC?

    To the external keyboard, I'd guess... isn't that what the original post was about?

     



  • What is wrong with you people?

    From left to right:

    1. USB male A to female A extension lead, probably used to keep the blue cube from blocking both USB ports
    2. (As pictured above) a "blue cube" active PS/2 to USB adapter, with male A to female PS/2
    3. USB to PS/2 passive adapter, male PS/2 to femlale USB
    4. Male A USB lead from keyboard

    None of the above are anything but cromulent. The WTF is that the only way to get the USB keyboard to work on a USB computer is via PS/2. Obviously this won't work if the keyboard's controller doesn't have PS/2 support.



  • @Daniel Beardsmore said:

    What is wrong with you people?
    It wasn't quite clear from the image that the cable was a USB extension (female to male), because its female end — as pictured — looks like a male plug* connected to a female socket* on the "blue cube".

    It was also not immediately clear to some people that the picture and the case you were describing were separate incidents. I too had to think twice.

    Whether this means you're a bad writer or we're all bad readers is discussable; FWIW I'm actually on your side on this one.

    *Pardon the unnecessary redundancies.


  • I thought the "Just came across …" followed by a link to the source of the image and its explanation was a bit of a giveaway – I didn't inline their image to take a sliver of load off their poor server.



  • @Daniel Beardsmore said:

    <font size="1"> +0.25 Internets for anyone who actually remembers that</font>

    Good old days. PPP, Gopher, Wais, iCab. Much better than a Teletype. Now where can I get this 0.25 Internets, and how much is that in Archies?



  • @Daniel Beardsmore said:

    I thought the "Just came across …" followed by a link to the source of the image and its explanation was a bit of a giveaway – I didn't inline their image to take a sliver of load off their poor server.

    Hey buddy, I clicked the link, it said, "this server is down." So you suck at WTFs no go away and be a curmudgeon and talk about 30 year old keyboards in a confusing manner somewhere else.

    (The link does seem to be working now, but it wasn't when your post was confusing the fuck out of everybody yesterday.)



  • 30-year old keyboards? The one that needs the depicted adapter arrangement is a brand new one.



  • @Daniel Beardsmore said:

    30-year old keyboards? The one that needs the depicted adapter arrangement is a brand new one.

    Since every single word I type must be taken absolutely literally, I approve of this response.



  • @Cassidy said:

    Nope - not used enough "white goods" to bash them

    That was a generic "you" I used there :)

    @Cassidy said:

    Okay, I fail at picture scrutinisation.... it looked to me like a USB-A plug (male) that went into the purple's socket (oo-er), rather than the purple bit having the USB-A plug connected to the USB extension cable.

    Seems not


    Now it makes sense … Like many others here it looked to me like the USB cable on the right plugs into the cube, rather than the other way around — the cable is really a USB extension cord, then.



  • @Gurth said:

    Now it makes sense … Like many others here it looked to me like the USB cable on the right plugs into the cube, rather than the other way around — the cable is really a USB extension cord, then.

    I only guessed by comparing the thicknesses of each that the leftmost USB connector was an inline socket, then hunting down an image of the cube to verify.



  • You can also just see the two indentations in the metal of the plug, which would not be in that spot if the plug was at the end of the cable.

    Yes, we have nothing better to do …


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