I was donated a 7" China Allwinner A20 dual core tablet. It has a build "wing-k70 eng 4.2.2 JDQ39". The unit has a a built in host port, but it seems that onlthing reconized is a USB drive. Has anyone been able to place a custom ROM on one of these tablets? I am looking for support for CP210X USB drivers and drivers to support a sprint 3G dongle. It is known as a AM721 and an A70x. Any help or direction would be great!!