if it lists the device as eth0, then you need to be typing eth0 instead of ath0
ath0 is for wireless devices with an atheros chipset only
I might be wrong, but I think your card's chipset is the SiS163u. You might have to use ndiswrapper. (I couldn't find a native linux driver for the chipset on google)
If you're going to get a wireless dongle, I suggest the Alfa AWUS036H.