h6. [[OS SWI Calls]] h6(. » [[OS_Byte]] h6((. » OS_Byte 2 h2. OS_Byte 2 h5. (SWI &06) |_<^{width:3em}. Entry | | |<^. R0|<^. 2 | |<^. R1|<^. [[Input Streams|Stream selection]] | |_<^{width:3em}. Exit|_<^. | |<^. R0|<^. Preserved | |<^. R1|<^. Value before being overwritten | |<^. R2|<^. Corrupted | h4. Use The purpose of this call is to select the device from which all subsequent input is taken by [[OS_ReadC]]. h4. Notes On exit only 0 or 1 can be returned, so 0 may also mean 2. The state of this variable can be read with [[OS_Byte 177]]. If Exec is enabled (see [[OS_Byte 198]]) then the Exec file handle is used as the current input stream. h4. See also * [[Input Streams]] * [[OS_Byte]] * [[OS_Byte 177]] * [[OS_Byte 198]] * [[OS_ReadC]]