Sega Genesis Model 1 to Sega CD Model 2 extender review! Classic Game Room review the SEGA CD MODEL 2 to SEGA GENESIS MODEL 1 EXTENDER review! Fit your Model 1 Mega Drive onto your Model 2 Mega CD with this handy piece of plastic that extends the length of the base of the Model 2 Sega CD add-on. This Sega CD extension doesn't do anything for the performance, but it does make it look better (although you could also spend that $$ on new games like TRUXTON)