Is the emachines KB-9908 a mechanical keyboard or rubber dome?



Yes, a lot of modern motherboards still come with them. Ive especially noticed it with AMD. You aren't going to find a classic mechanical keyboard that isn't PS/2.
 


I couldn't tell you, but I'd guess "No", it's not that old. You'd know if pushed the button right away. Mechanical sounds mechanical.

Or just take a car key and pop one of the keys out and take a look.