Sega System E
From Sega Retro
The Sega System E is an arcade platform produced by Sega between 1985 and 1988. It is based upon the Sega Master System hardware, using a Z80 as its main CPU, but with superior VDP hardware. As such, several System E games received accurate home conversions on the Master System.
The system is interesting as the main CPU is stored on the game cartridge or secondary PCB (not sure which) rather than on the board itself, allowing for things such as Z80 chips with built-in encryption technologies.
List of Games