[TYPO3-mvc] Using existing database tables in a model

[Mario Beiser]

Hi there,

just tried to have some output of an existing database table in a 
projekt like e.g. tt_news.

Therefore I used a a mapping like it is done in the extbase core for 
frontend users. When I try to print out my frontend user everything 
works fine. 

My question is, how it is possible to have existing tables as a base for 
a model class? Just the same way the frontend user thing in the 
Extbase-Extension is done?

So the typoscript-mapping is all I have to do? 

Perhaps someone has done this before.
Regards
Mario