another Megadrive thread from me so,the console says it needs 10 DC 1,2 A and on the power supply it reads "9V 1A" is this going to damage the unit in the long run? thanks in advance
Nah, you should be fine. All electrical goods are required to have a minimum of 10% voltage tolerance. So you should be able to use 9V - 11V psus. (Then again I'm not sure if these rules were in place when the MD came out.)
It should be fine but it's strange it says 10V. The Model 1 adapter clearly says 9VDC with Negative Center. The Model 2 I believe says 10VDC with Positive Center. Be sure that the polarity is correct. But 9v or 10v, the regulator inside the system I think is going to be putting that down to 5v anyway if I remember correctly. I know with Copiers they often say 9v ~ 12v, but you should use 9v on those as anything higher is just excess heat which is bad.
Megadrive PSUs come in many flavours from 9 to 10.5V, the voltage regulator inside the megadrive will make sure it gets the correct voltage, you could feed in 15V at 700ma and it'll still work but it would get rather hot. As long as you feed in around 9V at 1A then everything will be fine.