h6. [[OS SWI Calls]] h6(. » [[OS_Byte]] h6((. » OS_Byte 213 h2. OS_Byte 213 h5. (SWI &06) |_<^{width:4em}. Entry | | |<^. R0|<^. 213 (&D5) | |<^. R1|<^. EOR value | |<^. R2|<^. AND value | |_<^{width:4em}. Exit|_<^. | |<^. R0|<^. Preserved | |<^. R1|<^. Previous frequency | |<^. R2|<^. Bell duration (see [[OS_Byte 214]]) | h4. Use The purpose of this call is to read or write the sound frequency (pitch) for the bell. h4. Notes This call reads or sets the bell pitch, which is a [[Sound Pitches|BBC style frequency]] in the range 0-255. The default pitch is 100. To read/write the bell channel use [[OS_Byte 211]]. To read/write the volume use [[OS_Byte 212]]. To read/write the duration use [[OS_Byte 214]]. h4. See also * [[OS_Byte]] * [[OS_Byte 211]] * [[OS_Byte 213]] * [[OS_Byte 214]] * [[Sound Pitches]]