h6. [[OS SWI Calls]] h6(. » [[OS_UpCall]] h6((. » OS_UpCall 15 h2. OS_UpCall 15 h5. (SWI &33) |_<^{width:4em}. Entry | | |<^. R0 |<^. 15 (&0F)| |<^. R1 |<^. [[FileSwitch]] stream handle | |_<^{width:4em}. Exit | | |<^. R0 |<^. Preserved | |<^. R1 |<^. Preserved | h4. Use The purpose of this call is to inform your application when there is data entering a previously empty buffer. h4. Notes This service is issued when there is data entering a previously empty buffer. Only devices opened for read will receive this UpCall. h4. See also * [[FileSwitch]] * [[OS_UpCall]]