I replaced an "ATEN 2-port KVM Switch CS-62A" (which accepts PS/2 keyboard and mouse) with a "Level One KVM Switch KVM-0221" (which accepts USB keyboard and mouse).

The Level One KVM-0221 is an annoyingly designed, problematic KVM Switch. It was a complete disappointment and did not switch correctly or function properly, so after 5 days, I returned it and bought an ATEN KVM CS62US that works PERFECTLY.

Simply put, the KVM-0221 does not function as a KVM Switch. It does not perform the basic functions automatically when connected to 2 PCs. Specifically, it presented the following "problems":

1) When only the 1st computer is on and the 2nd is off, and I switch from the 1st to the 2nd using the keyboard, I cannot switch back to the 1st using the keyboard ("Scroll Lock + Scroll Lock"). The reason is that the keyboard does not work at that moment because it does not have power. This is because the KVM-0221 is powered by the PC it is connected to. And since the 2nd PC is off, the KVM does not receive power, and therefore, neither does the keyboard. So, I cannot switch back to the 1st. To switch back to the 1st, I have to press the "1" button on the KVM-0221. Not a very elegant solution if the KVM is not near you. This problem DID NOT exist with the previous ATEN switch I had. With the ATEN, I could switch between 2 PCs at any time, even if one of them was off. If I had known that the KVM-0221 does not support such a function, I would NOT have bought it. I would have bought the ATEN KVM CS62US from the beginning.

2) When the 2nd PC remains off, then upon starting the 1st PC, the keyboard is activated (it lights up), but the monitor remains off for an unknown reason. And I cannot see anything. It does not automatically recognize that the 1st PC is turning on in order to connect the monitor to it. To be able to see the monitor, I need a "trick"! I have to unplug the 1st PC from the power outlet for 15 seconds and then turn it on after pressing the "1" button on the KVM. If I don't do this, the monitor does not connect when the 1st PC turns on. The strange thing is that after the 1st PC turns on, suddenly the KVM switches to the 2nd PC for no reason, which is still off. And I have to press the "1" button on the KVM again to restore the keyboard, monitor, and mouse. This is incredibly annoying!

3) If I turn off the power to both PCs and then turn it back on, strangely, the keyboard lights up without any PC being on. If I turn on the 1st PC, after a while, the KVM automatically switches to the 2nd PC, which is still off. It does this twice, so I have to press the corresponding "1" button on the KVM each time. I don't understand why it does this. But it is a purely annoying malfunction.

4) In addition to "Scroll Lock + Scroll Lock" for switching, the same can be done with "Num Lock + Num Lock"! Something that is not mentioned anywhere!

Conclusion: A poorly designed product that does not perform the functions that a KVM Switch should. However, its price is not cheap at all to be considered a bargain and overlook its failure to perform basic functions. That's why I do not recommend it, as there are other competitive KVMs on the market that behave much better and are more reliable. Overall, I consider buying it a waste of money. Ultimately, it was the worst choice I could have made for a KVM switch. Choose something reliable that works correctly. Stay away. I returned it as unacceptable within 5 days of purchasing it. And I bought an ATEN KVM CS62US that works perfectly.

P.S. Note that the Aten CS62A that I used for at least 8 years never had any problems and was an amazing product. Flawless performance. Completely satisfied. I only changed it because it only accepts PS/2 keyboard and mouse and I wanted to switch to USB keyboard and mouse.