How do I know if I have an Early Genesis?

So in August I got a Genesis. High Definition graphics model, extension port in the back. Only 1 minor scratch I'll remove eventually.

It seems like I have a year 1 Genesis.

A friend told me if booting it up it says "By or under license from Sega Enterprises LTD" it's one of the first.
Mine does say it.

If this is from the mythucam first batch is there any advtanage I have vs a later Model 1 or a Model 2?

 

I used this guide to tell all mine apart.

 

Yep looks like I have a first run Genesis.

 

It's the other way around - that "licensed by Sega" screen (aka TMSS) was added later and the non-TMSS units are the early ones.

So if your machine has that "High definition graphics" text and also has TMSS, then it's an early unit, but not the initial release.

 

That's what I thought, earliest models don't have any text at the beginning, as TMSS was later added to try to prevent bootleg carts.

 

Yours was made sometime around the launch of Sonic The Hedgehog.

Look for the longer FCC ID: FJ846EUSASEGA if you want the original run.

 

Label

 

That is the correct FCC ID for the later TMSS model.