Take the 2-minute tour ×
Super User is a question and answer site for computer enthusiasts and power users. It's 100% free, no registration required.

I have an old keyboard I'd like to use on recent devices (no PS2 port). But it's still on a 5 pin din plug. I tried to plug that in a Din-2-PS2 adapter and that in PS2-2-USB, but the keyboard was not recognized at all. Is there anything I have to consider here? Should it work, or is there a reason why it cannot work?

share|improve this question

1 Answer 1

up vote 8 down vote accepted

There is a simple reason why it does not work. The keyboard does not talk the USB protocol.

With most mice and keyboards you have the following options:

  • PS/2 mouse, using the PS/2 protocol. Works only in PS/2 plug.
    Does not work with a PS/2 to USB plug.
  • USB mouse, using the USB protocol. Works only via and USB plug.
  • A mouse understanding both PS2 and USB, auto-detecting which wiring is in use. This one will work both when plugged into a PS/2 port and when (with a convertor) plugged into an USB port.

The same is true for keyboards, though there are many more mice that support both PS/2 and USB than keyboards.

Now your keyboard has a old din plug. That means it is probably very old. Thus it is unlikely that it groks both the pre-PS2 din way and the modern USB method. This is why it fails.

If you want to get it to work you will need to add an active device which speaks both the old protocol and the new one. A mere plug which connects a few cables will no do.


Some nice picture to help me gain rep let the younger readers understand just what AT Din5, PS/2 etc is:

enter image description here

And some convertors with active electronics inside them. These will work, even for old PS/2 keyboards. I never tested them with an additional AT keyboard plug.

enter image description here

share|improve this answer
    
So you are suggesting to get a passive DIN2 to PS2 connector and plug that in an active PS2 to USB plug? –  uwe Mar 25 '13 at 17:35
    
I am suggesting that that may work. But as I wrote, I never actually tested that. I do have used things like the bottom left 'active cable` and they work even with very old keyboards which do not understand USB. (In fact, I am typing that from the IBM model M keyboard I tested it with. Made in 1991 and still working). However going back to DIN5 keyboards is out of my experience. I do not know if those are fully compatible with PS/2. (with fully I mean: If only the form differs, but the signals are compatible). –  Hennes Mar 25 '13 at 17:42
1  
It worked. Buying an active PS2 to USB plug did the trick. I'm now typing with one of the first Cherry G80/3000 with a DIN5 plug on Windows 8 :) –  uwe Mar 28 '13 at 8:40
    
Yay! (Still typed from a 24 year old model M). –  Hennes Mar 28 '13 at 11:58

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.