In order to format the Backup RAM Cart, you must load a game into the Sega CD. 

On the power-up screen, press the C button to access the system menu as seen above. 

*The menu screenshots shown are representative of the North American Model 2 Sega CD. 

On a Model 1 Sega CD select “OPTION” instead of “MEMORY”. 

*Note that the “MEMORY” option will not be available if no game is loaded into the Sega CD. 

Follow the on-screen instructions to format the Backup RAM Cart. 

From here, you may also copy save files to and from the Backup RAM Cart.