PS/2 Keyboard > USB?

  Looks like an adapter to allow me to connect my PS/2 keyboard to a
desktop is no trivial thing.  $10 plus seems a little dear to me.
Is there no cheaper way to go?  Maybe not.

Thanks

Grumpy

 On Fri, 08 Mar 2013 15:55:30 -0500, Grumpy@Oldman.com wrote:


I am pretty sure that only PS/2 keyboards that are *made* to be able
to work with (usb-)adapters work with these things. And then probably
they work only with their own usb-adapters,often delivered with the
PS/2 mobo (like those of Logitech) and seldom sold separately .

Massimo

  On 3/8/2013 4:32 PM, Massimo wrote:

There are active and passive adapters.  I believe you're correct if  
you're talking about passive adapters, that look like this:

http://img.tomshardware.com/us/2005/11/23/pc_interfaces_101/ps2_usb.jpg  

Active adapters are meant to work with any PS/2 keyboard and/or mouse:

http://www.monoprice.com/products/subdepartment.asp?c_id=104&cp_id=10404&cs_id=1040401  

Of course, that's no guarantee they'll work with any given peripheral,  
but I've had luck with them.

 wrote:

I have a couple of these, and they do not work with the PS/2 keyboards
I have.


At least the prices on this site beat the prices I found and did not
like.



Thank you  

Grumpy

 Grumpy@Oldman.com wrote:

This adapter is passive, and there's nothing inside the plastic connector
body, but connector pins. But these adapters only work on "dual personality"
hardware. My Logitech mouse supports both PS/2 and USB protocols - and all
it takes is this adapter, to adapt to a different computer connector. The
mouse works the magic, not the adapter. The adapter just gets my mouse
connected to a different set of pins. At power up, the mouse can sense the
difference between the two interfaces.

http://www.newegg.com/Product/Product.aspx?Item=N82E16812200272  

*******

But you're probably referring to one of these. These have a
Chesen chip inside. The Chesen chip is actually an 8 bit microprocessor,
complete with firmware and RAM. All for the purposes of protocol
conversion. It's well worth the $10. After all, the cable has
three connectors on it, so even the connectors add a bit
to the price, and that doesn't leave much money to pay for
the processor inside the white blob.

http://images17.newegg.com/is/image/newegg/12-119-237-Z02? $S300W$

When you get the PCI card version, it's easier to see the Chesen
chip in there.

On this example PCI card, the big chip on the right, does PCI to USB2.
The chip nearest the faceplate, is the Chesen processor that does
dual PS/2 to USB. So two chips are needed in total, to go from PCI to PS/2.

http://images10.newegg.com/NeweggImage/productimage/15-124-045-06.jpg  

The Chesen CSC0101A-S16 chip on the left is a bit clearer here.

http://images10.newegg.com/NeweggImage/productimage/15-124-045-03.jpg  

This is a block diagram, for the processor chip. Apparently, it's
out of production now, so if you need a dual PS/2 to USB, buy it now!
Inside is a 65C02 processor. The SCLK1/SDATA1 and SCLK2/SDATA2 pins
are for the PS/2 keyboard and mouse, clock and data interface.

http://ts1.mm.bing.net/th?id=H.4730890238691272&pid=15.1  

The firmware on the Chesen chip, changed with time. The very first
chips to be released, there was a bug where the converter would
"freeze up" after about ten minutes. The version that was for sale
maybe a year later, seemed to fix that. Always read the customer
reviews, to see if the product is still worthy.

    Paul