{
{    The purpose of this request is to convert a logical file address
{  (byte address) to the corresponding logical device address for a read
{  operation.
{
{        PROCEDURE DMP$READ(P_FDE, BYTE_ADDRESS, LENGTH_IN_BYTES,
{                         DEVICE_ADDRESS,STATUS)
{
{ P_FDE:(input)  This parameter specifies a pointer to the file descriptor
{                entry for the file.
{
{ BYTE_ADDRESS:(input)  This parameter specifies the logical file address to be
{                       converted.
{
{ LENGTH_IN_BYTES:(input)  This parameter specifies the length of the read
{                          request.
{
{ DEVICE_ADDRESS:(output)  This parameter returns the logical device address
{                          that corresponds to the logical file address.
{
{ STATUS:(output)  This parameter returns the request status.
{
