putchar and printf problem

Hi,

I'm using Silabs IDE and KEIL C 51.

I want to use printf, I know that printf is using putchar. So I've modified the file PUTCHAR.C to meet my HARDWARE UART the file PUTCHAR.C is located in the c:keil\C51\lib

But its not working. What is the correct method ?

Do I need to ADD the putchar file to my project ?

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