The Sega Dev Card by Western Technologies was a third party development kit that functioned in a similar way to modern day Flash Cartridges. It connects to the developers PC (running MS-DOS) via a port on the back of the cartridge 1.
The developer could then run
SEGALOAD GameName.bin to load a compiled Sega Mega Drive game ROM file. It can also debug games using breakpoints and memory dumps 1.
Developed for Electronic Arts in 1989, the SPROBE combines a Sega Mega Drive and a development board.
Latching onto the Mega Drive cart interface, it adds a cartridge emulator as well as a debug / development capability using a PC card link. This hardware is one of the reasons for EA’s early dominance in Sega Genesis gaming 2.