Flashing an Arduino Mega 2560 with firmware stored on a micro SD card | Mechatronics Craze
Arduino MEGA 2560 32Kb RAM shield | Hackaday.io
Arduino: fast external SPI Flash memory – Renzo Mischianti
Amazon.com: Mega ADK R3 ATmega2560 Module Compatible ADK With USB Cable - Compatible SCM & DIY Kits Module Board - 1 x Compatible Arduino Mega ADK R3, 1 x USB cable : Electronics