I'm not sure what you mean by processed. If he just got there from County, he's in reception and that takes about 3 to 4 months. Once he's classified, he'll be shipped to a mainline prison - or fire camp or CCF or whatever depending on his sentence and custody level.
If you got a letter from him, you now have his CDC# and housing, so you can write to him and you can put money on his books.