Hello to all, I found yesterday the declacation to the __SEGGER_RTL_X_file_write() in corresponding __SEGGER_RTL.h. So I included the following function in my project and it works. C Source Code (5 lines) But i can't replay this yesterday, because my registration for this forum was approved today. So I saw the new description for this issue form Nino today. But I have further question: What ist the definitin for the return value of __SEGGER_RTL_X_file_write(..)? Kind regards AxKe