h6. [[BufferManager]] h6(. » [[BufferManager SWI Calls|SWI Calls]] h6((. » [[Buffer_InternalInfo]] h6(((. » [[Buffer Service Codes|Service Codes]] h6((((. » Buffer Service Code 7 |_<^{width:3em}. Entry | | |<^. R0 |<^. 7 (Reason code) | |<^. R1 |<^. Internal buffer ID | |<^. R12 |<^. Value returned by [[Buffer_InternalInfo]] | |_<^{width:3em}. Exit | | |<^. R2 |<^. Number of free bytes in buffer | h4. Use This call returns the number of free bytes in a buffer.