An Arduino and video game enthusiast has documented a method of reading the contents of Sega Megadrive video game cartridges using an Arduino Mega board and some simple hardware. A Mega is required due to the number of connectors on the game cartridge, which connects to the circuit via an old ISA slot from a '486-era motherboard. Although simple, this project could possibly lead to methods of backing up the old Sega cartridges.
When projects such as the Sega cartridge reader outgrow the normal Arduino-compatible boards, running out of program and flash memory space, or you're stacking on Ethernet and microSD shields, or all at once - it's time to upgrade to the Freetronics EtherMega:
Quite simple the EtherMega is the fully-loaded Arduino-compatible board on the market today. Apart from being completely Arduino Mega2560-compatible, it includes full Ethernet interface, a microSD card socket, full USB interface, optional Power-over-Ethernet support and still has a circuit prototyping area with extra I2C interface pins. So if your project is breaking the limits, upgrade to the EtherMega today.