{   This procedure is called to erase an arbitrary length of tape.
{
{ NOTE:  Due to hardware restrictions, tape can only be erased in multiples of
{       approximately three inches.  This procedure will erase the minimum
{       number of 3-inch areas necessary to erase the length specified.
{
{       BAP$TAPE_BM_ERASE_BLOCK(FILE_IDENTIFIER, BLOCK_LENGTH, FAILURE_MODES,
{       STATUS)
{
{  FILE_IDENTIFIER (Input):  The file identifier for the file.
{
{  BLOCK_LENGTH:  (Input) The number of bytes which correspond to the desired
{        erased length.
{
{  FAILURE_MODES:  (Output) Detailed information on any tape I/O error.
{
{  STATUS: (Output) Request status.
