h6. [[OS SWI Calls]] h6(. » [[OS_Byte]] h6((. » OS_Byte 152 h2. OS_Byte 152 h5. (SWI &06) |_<^{width:3em}. Entry | | |<^. R0|<^. 152 (&98) | |<^. R1|<^. [[Buffer Numbers|Buffer number]]| |_<^{width:3em}. Exit|_<^. | |<^. R0|<^. Preserved | |<^. R1|<^. Preserved | |<^. R2|<^. Next byte in buffer, corrupted if buffer empty | |\2<^. C flag set if buffer is empty, otherwise clear | h4. Use The purpose of this call is to check whether a given buffer is empty, and if a byte is available return it without removing it from the buffer. h4. Notes The buffer number is *not* validated - undefined results (rather than an error) occur if a bad buffer number is passed. h4. See also * [[Buffer Numbers]] * [[OS_Byte]]