It’s an Arduino shield that adds a Linux SoC, WiFi, Ethernet, and USB Host to any Arduino board from the Uno, to the Duemilanove and Mega ... with the Dragino HE module being the most difficult ...
[Andy] stuffed some more RAM onto an Arduino Mega and his three-part walk through ... The build is centered around a 512K × 8 SRAM module [PDF warning]. Because the RAM is divided up into ...