So in the end you will really have AT-to-PS/2-to-USB?

Too many adapters could cause trouble.

But... I think I have what you need in my office.  You can try one 
before you buy.  We use them to connect new Dell computers (USB-only) to 
existing PS/2 KVM switches.

Just make sure you get one with a female PS/2 connector.

They cost under $16, sometimes with free shipping.  Don't feel 
ridiculous.  If you want to double the weight to a full ounce, throw in 
  a 1GB thumb drive for another $10.  :)

- Dan

John Li wrote:
> Hey all,
> I have a nice clickety-clackety keyboard that I'd like to use on my
> laptop. It has a 5-pin AT connector, but I have an AT-to-PS2 converter.
> However, my laptop only has USB ports, so I need a PS2-to-USB converter.
> I've found a few places offering such a converter online, but I would
> feel ridiculous having a half-ounce part shipped to me. Anyone know how
> difficult it'd be to splice this together myself?
> Thanks!
> Nile