Where do you go to make powder FireRed?

Answer 1

Once you get the powder jar hook up the wireless adapter to your GBA and have a friend do it also both players should go upstairs in the Pokemon center and speak to the lady behind the far right counter she will save your game then ask you which room to enter go to Berry Crush then have one player become leader and the other join the leaders group confirm the link by pressing A then you will enter the room. Have both players insert any berry in the machine allthough it's highly recommended to choose the ones that say "it's a good ingredient to make berry powder" but like i said you can choose any berry. Once the berries are inserted a countdown will start when it says GO start pressing the A button repeatedly and have your friend do the same keep pressing until the machine reaches the bottom once that happens you will receive berry powder keep making more until you have plenty to spend with the old man that gave you the powder jar.