TP.RD9 - read a 9-channel tape.

B:
   status = tp.rd9( unit, buffer, bytes );

C:
   int tp_rd9(FILE *unit, void *buffer, int bytes );

unit: is an open I/O unit associated with a 9-channel tape.
buffer: points to a buffer into which TP.RD9 places the data it reads.
bytes: is the maximum number of bytes of data you want to read.
status: is the number of bytes read, if the I/O operation was successful. If an I/O error occurs, "status" receives the negative of the major error status. A status of zero indicates that an EOF (tapemark) was read.

TP.RD9 reads the requested number of bytes from a 9-channel tape into the specified buffer.