uploading software to a long chain of arduinos. How?

Other Hardware 3rd Party Boards
1

I want a (long) chain of Arduinos... if possible I want to program them all at ones. Who knows how to do that?

2

You might want to help the forum by describing in some detail what the long chain of Arduinos is being used for, which Arduinos they are, how they are connected, and what is 'long' ?

3

I still need to decide which Arduino I will use. Now I am using Arduino UNO. But I can use another one if needed.

I think about connecting the Arduinos with RST232. But also here I am flexible.

How long? Well maybe even 100 Arduinos in a daisy chain. So it will be a pain to reprogram them one by one.

==>> Is there a way to program a lot of Arduinos in one go?