question about KVM switches

Hi guys. Quick question.

I was wondering if there is such a thing as a KVM (keyboard video mouse) switch that lets you use one keyboard simultaneously on both computers. Meaning that If I for example hit the "1" key, both computers at the same time (not requiring me to switch and push the key two separate times) will type the number 1. So if I were to type what I am typing right now, it would be simultaneously typing it on both computers. is this even called a KVM? or is it even possible?
My understanding of KVMs is vague, so I apologize if this is a dumb question.

 

Yes there is a Belkin 2 Port KVM switch which SHOULD allow u 2 run 2 computers with 1 keyboard 1 mouse and one monitor. I bought one through Amazon as I want to run my Advent machine with Vista OS and a E1 Machine which has Win XP as lots of programs I have on the E1 will not run on Vista - which I expletive deleted hate! I am on Virgin cable and need to be able to use it for both machines.
However, the KVM simply does not work on my system. for one thing both my machines have PS2 keyboard connection. The KVM needs a USB. I bought a converter but that does not seem to work for me. I'm trying to return the switch to Belkin -but you may have better luck than me -or maybe I'm just stupid or old my first machine was a Sinclair Spectrum !!!

 

lol. yah that is pretty.. old.

Ive been doing some more digging around and I am also starting to wonder if just splitting the usb connection to the 2 computers would accomplish the same thing for cheaper, seen how I have no need to switch to one or the other, and would rather them both always be on at the same time.