BulkLen = 18;
  DataInTransfer();
}


/*
 *  MSC SCSI Inquiry Callback
 *    Parameters:      None (global variables)
 *    Return Value:    None
 */

void MSC_Inquiry (void) {

  if (!DataInFormat()) return;

  BulkBuf[ 0] = 0x00;          /* Direct Access Device */
  BulkBuf[ 1] = 0x80;          /* RMB = 1: Removable Medium */
  BulkBuf[ 2] = 0x00;          /* Version: No conformance claim to standard */
  BulkBuf[ 3] = 0x01;

  BulkBuf[ 4] = 36 - 4;         /* Additional Length */
  BulkBuf[ 5] = 0x80;          /* SCCS = 1: Storage Controller Component */
  BulkBuf[ 6] = 0x00;
  BulkBuf[ 7] = 0x00;

  BulkBuf[ 8] = 'T';           /* Vendor Identification */
  BulkBuf[ 9] = 'o';
  BulkBuf[10] = 'p';
  BulkBuf[11] = 'l';
  BulkBuf[12] = 'o';
  BulkBuf[13] = 'w';
  BulkBuf[14] = ' ';
  BulkBuf[15] = ' ';

  BulkBuf[16] = 'A';           /* Product Identification */
  BulkBuf[17] = 'T';
  BulkBuf[18] = '9';
  BulkBuf[19] = '1';
  BulkBuf[20] = 'S';
  BulkBuf[21] = 'A';
  BulkBuf[22] = 'M';
  BulkBuf[23] = '7';
  BulkBuf[24] = 'S';
  BulkBuf[25] = ' ';
  BulkBuf[26] = 'A';
  BulkBuf[27] = 'R';
  BulkBuf[28] = 'M';
  BulkBuf[29] = 'M';
  BulkBuf[30] = 'P';
  BulkBuf[31] = '3';

  BulkBuf[32] = '1';           /* Product Revision Level */
  BulkBuf[33] = '.';
  BulkBuf[34] = '0';
  BulkBuf[35] = ' ';

  BulkLen = 36; 
  DataInTransfer();
}


/*
 *  MSC SCSI Mode Sense (6-Byte) Callback
 *    Parameters:      None (global variables)
 *    Return Value:    None
 */

void MSC_ModeSense6 (void) {

  if (!DataInFormat()) return;

  BulkBuf[ 0] = 0x03;
  BulkBuf[ 1] = 0x00;
  BulkBuf[ 2] = 0x00;
  BulkBuf[ 3] = 0x00;

  BulkLen = 4;
  DataInTransfer();
}


/*
 *  MSC SCSI Mode Sense (10-Byte) Callback
 *    Parameters:      None (global variables)
 *    Return Value:    None
 */

void MSC_ModeSense10 (void) {

  if (!DataInFormat()) return;

  BulkBuf[ 0] = 0x00;
  BulkBuf[ 1] = 0x06;
  BulkBuf[ 2] = 0x00;
  BulkBuf[ 3] = 0x00;
  BulkBuf[ 4] = 0x00;
  BulkBuf[ 5] = 0x00;
  BulkBuf[ 6] = 0x00;
  BulkBuf[ 7] = 0x00;

  BulkLen = 8;
  DataInTransfer();
}


/*
 *  MSC SCSI Read Capacity Callback
 *    Parameters:      None (global variables)
 *    Return Value:    None
 */

void MSC_ReadCapacity (void) {

  if (!DataInFormat()) return;

  /* Last Logical Block */
  BulkBuf[ 0] = ((MSC_BlockCount - 1) >> 24) & 0xFF;
  BulkBuf[ 1] = ((MSC_BlockCount - 1) >> 16) & 0xFF;
  BulkBuf[ 2] = ((MSC_BlockCount - 1) >>  8) & 0xFF;
  BulkBuf[ 3] = ((MSC_BlockCount - 1) >>  0) & 0xFF;

  /* Block Length */
  BulkBuf[ 4] = (MSC_BlockSize >> 24) & 0xFF;
  BulkBuf[ 5] = (MSC_BlockSize >> 16) & 0xFF;
  BulkBuf[ 6] = (MSC_BlockSize >>  8) & 0xFF;
  BulkBuf[ 7] = (MSC_BlockSize >>  0) & 0xFF;

  BulkLen = 8;
  DataInTransfer();
}


/*
 *  MSC SCSI Read Format Capacity Callback
 *    Parameters:      None (global variables)
 *    Return Value:    None
 */

void MSC_ReadFormatCapacity (void) {

  if (!DataInFormat()) return;

  BulkBuf[ 0] = 0x00;
  BulkBuf[ 1] = 0x00;
  BulkBuf[ 2] = 0x00;
  BulkBuf[ 3] = 0x08;          /* Capacity List Length */

  /* Block Count */
  BulkBuf[ 4] = (MSC_BlockCount >> 24) & 0xFF;
  BulkBuf[ 5] = (MSC_BlockCount >> 16) & 0xFF;
  BulkBuf[ 6] = (MSC_BlockCount >>  8) & 0xFF;
  BulkBuf[ 7] = (MSC_BlockCount >>  0) & 0xFF;

  /* Block Length */
  BulkBuf[ 8] = 0x02;          /* Descriptor Code: Formatted Media */
  BulkBuf[ 9] = (MSC_BlockSize >> 16) & 0xFF;
  BulkBuf[10] = (MSC_BlockSize >>  8) & 0xFF;
  BulkBuf[11] = (MSC_BlockSize >>  0) & 0xFF;

  BulkLen = 12;
  DataInTransfer();
}


/*
 *  MSC Get Command Block Wrapper Callback
 *    Parameters:      None (global variables)
 *    Return Value:    None
 */

void MSC_GetCBW (void) {
  DWORD n;

  for (n = 0; n < BulkLen; n++) {
    *((BYTE *)&CBW + n) = BulkBuf[n]; 
  }
  if ((BulkLen == SIZE_MSC_CBW) && (CBW.dSignature == MSC_CBW_Signature)) {
    /* Valid CBW */
    CSW.dTag = CBW.dTag;
    CSW.dDataResidue = CBW.dDataLength;
    if ((CBW.bLUN != 0) || (CBW.bCBLength < 1) || CBW.bCBLength > 16) {
fail: CSW.bStatus = CSW_CMD_FAILED;
      MSC_SetCSW();

    } else {
      switch (CBW.CB[0]) {
        case SCSI_TEST_UNIT_READY:
          MSC_TestUnitReady();
          break;
        case SCSI_REQUEST_SENSE:
          MSC_RequestSense();
          break;
        case SCSI_FORMAT_UNIT:
          goto fail;
        case SCSI_INQUIRY:
          MSC_Inquiry();
          break;
        case SCSI_START_STOP_UNIT:
          goto fail;
        case SCSI_MEDIA_REMOVAL:
          goto fail;
        case SCSI_MODE_SELECT6:
          goto fail;
        case SCSI_MODE_SENSE6:
          MSC_ModeSense6();
          break;
        case SCSI_MODE_SELECT10:
          goto fail;
        case SCSI_MODE_SENSE10:
          MSC_ModeSense10();
          break;
        case SCSI_READ_FORMAT_CAPACITIES:
          MSC_ReadFormatCapacity();
          break;
        case SCSI_READ_CAPACITY:
          MSC_ReadCapacity();
          break;
        case SCSI_READ10:
          if (MSC_RWSetup()) {
            if ((CBW.bmFlags & 0x80) != 0) {
              BulkStage = MSC_BS_DATA_IN;
              MSC_MemoryRead();
            } else {
              USB_SetStallEP(MSC_EP_OUT);
              CSW.bStatus = CSW_PHASE_ERROR;
              MSC_SetCSW();
            }
          }
          break;
        case SCSI_WRITE10:
          if (MSC_RWSetup()) {
            if ((CBW.bmFlags & 0x80) == 0) {
              BulkStage = MSC_BS_DATA_OUT;
            } else {
              USB_SetStallEP(MSC_EP_IN);
              CSW.bStatus = CSW_PHASE_ERROR;
              MSC_SetCSW();
            }
          }
          break;
        case SCSI_VERIFY10:
          if (MSC_RWSetup()) {
            if ((CBW.bmFlags & 0x80) == 0) {
              BulkStage = MSC_BS_DATA_OUT;
              MemOK = TRUE;
            } else {
              USB_SetStallEP(MSC_EP_IN);
              CSW.bStatus = CSW_PHASE_ERROR;
              MSC_SetCSW();
            }
          }
          break;
        default:
          goto fail;
      }
    }
  } else {
    /* Invalid CBW */
    USB_SetStallEP(MSC_EP_IN);
    USB_SetStallEP(MSC_EP_OUT);
    BulkStage = MSC_BS_ERROR;
  }
}


/*
 *  MSC Set Command Status Wrapper Callback
 *    Parameters:      None (global variables)
 *    Return Value:    None
 */

void MSC_SetCSW (void) {

  CSW.dSignature = MSC_CSW_Signature;
  USB_WriteEP(MSC_EP_IN, (BYTE *)&CSW, SIZE_MSC_CSW);
  BulkStage = MSC_BS_CSW;
}


/*
 *  MSC Bulk In Callback
 *    Parameters:      None (global variables)
 *    Return Value:    None
 */

void MSC_BulkIn (void) {

  switch (BulkStage) {
    case MSC_BS_DATA_IN:
      switch (CBW.CB[0]) {
        case SCSI_READ10:
          MSC_MemoryRead();
          break;
      }
      break;
    case MSC_BS_DATA_IN_LAST:
      MSC_SetCSW();
      break;
    case MSC_BS_DATA_IN_LAST_STALL:
      USB_SetStallEP(MSC_EP_IN);
      MSC_SetCSW();
      break;
    case MSC_BS_CSW:
      BulkStage = MSC_BS_CBW;
      break;
  }
}


/*
 *  MSC Bulk Out Callback
 *    Parameters:      None (global variables)
 *    Return Value:    None
 */

void MSC_BulkOut (void) {

  BulkLen = USB_ReadEP(MSC_EP_OUT, BulkBuf);
  switch (BulkStage) {
    case MSC_BS_CBW:
      MSC_GetCBW();
      break;
    case MSC_BS_DATA_OUT:
      switch (CBW.CB[0]) {
        case SCSI_WRITE10:
          MSC_MemoryWrite();
          break;
        case SCSI_VERIFY10:
          MSC_MemoryVerify();
          break;
      }
      break;
    default:
      USB_SetStallEP(MSC_EP_OUT);
      CSW.bStatus = CSW_PHASE_ERROR;
      MSC_SetCSW();
      break;
  }
}