# usb keyboard in ps2 port?

## Oo.et.oO

i have an adapter that came with my old mouse.  as far as i can tell it's the same as a keyboard adapter... pin outs are the same

but it doesn't work.

i have a dell MM keyboard and it's usb. but i want to connect it to my ps2 KVM switch.  it doesn't seem to work.

anyone have any ideas?   intarweb search turns up a bunch of moronic questions that are related but no real answers.

thanks!

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## whig

The usb mouse -> ps/2 adapters are green. Keyboard ones are violet so that's what you want.

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## Oo.et.oO

thanks for your reply

on all the docs i've seen the pinouts are the same.  are you trying to say the machines care about the color?

or have you seen adapters where the pinouts are changed between the keyboard and mouse?

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## Carnildo

Most adapters are mechanical adapters that simply switch wires around.  If the keyboard doesn't speak both USB and PS/2, you can't use it with a mechanical adapter: you'd need a active adapter, and those cost more than the typical keyboard.

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## whig

I don't think ps/2 keyboard ports (ie protocols) are compatible with ps/2 mice ones. Hence a different usb adapter would be needed for each. But the adapters themselves are small and dirt cheap, I got more than a few mice ones lying around. But only two keyboard ones.

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## energyman76b

I support Carnildo.

That little green thingies are only mechanical. If the keyboard does not speak ps2, you are out of luck.

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## whig

So provide the OP the necessary pins to connect. Link?

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## energyman76b

 *whig wrote:*   

> So provide the OP the necessary pins to connect. Link?

 

don't you understand? if his keyboard does not speak ps2, it does not matter how he wires it, it does not work.

No need to post something. Just ask the vendor's support.

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## whig

What are the pin connections for a "good" keyboard? I'm interested.

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## energyman76b

 *whig wrote:*   

> What are the pin connections for a "good" keyboard? I'm interested.

 

why not open an adapter and look for yourself?

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## stp_1993

Let me disagree.

I have a USB keyboard and a PS2 KVM switch and a green USB->PS/2 adapter.

It all worked fine until TODAY, when the keyboard stopped working in X windows (but not in the console).

Seems like other people on the forums are having a similar problem. I am still troubleshooting  :Sad: 

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## whig

 *energyman76b wrote:*   

> why not open an adapter and look for yourself?

 I'm not game enough; I only have two of them and the package is moulded sealed.

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## Monkeh

I'm pretty sure the adapters are identical (just PC97 colour coded), but they're worthless if the USB device doesn't speak PS/2 (many do, some don't.).

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## whig

If I had a working multibox it could reveal pin connections.

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## Monkeh

 *whig wrote:*   

> If I had a working multibox it could reveal pin connections.

 

Considering USB has four pins, and PS/2 uses four pins (usually), and those four pins are the same for keyboard and mouse.. does it matter?

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## energyman76b

http://en.wikipedia.org/wiki/PS/2_connector

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