Whats the diff?

hey i have 2 sega system 1's

they look exactly alike except for 2 differences that i can see.

1 says *High Defenition Graphics* on the top and the other does not.

and the one that says HDG on the top had a EXT port on the back that looks like a 9pin serial connector.

Can anyone tell me what the differences are and why they made 2?

Here's a quick and simplified description.

The version with "high definition graphics was the first Sega Genesis console produced in the US.

It had the expansion port on the back (D9) to hook to a modem (it was only released in japan) internally it was pretty much the same as the later model 1 Genesis, except one thing, it had no licence check.

This means games not licenced by Sega could be used on the system.

The later run of Genesis model 1's dropped the ext port, lacked the "high definition graphics" label, and it had a new licence check OS chip.

If the Genesis found the proper code missing, the game would not load.

But, if it found the code, it will display "produced by or under licence from sega enterprises" on the screen, then the game will load.

The original "high def.." system is the more sought after of the two by modern Genesis players because of the ability to play the early unlicenced games.

I hope this helps.
yeah thanks a bunch.

lol i thought i had some boot leg genesis or something haha.

by the way do you know how they non-code checking genesis usually goes for?
About the same as the "protected" ones, because most sellers don't make a distinction between the different types of "Model 1" Genesis.
Actually, just because a Genesis says High Definition Graphics and has an ext. port doesn't mean that it doesn't have that OS rom (I have 2 like this). The only real test to see if it doesn't have it is to put in a game and see if the words : 'Produced or under licence from Sega" (or whatever) come up or not before the game starts. If these types of words don't come up, congratulations you have an early model Genesis/Mega Drive. If they do then your Genesis/Mega Drive has that OS rom.