harbour-core/harbour/contrib/hbnf/floptst.prg

/*
 * $Id$
 */

/*
 * File......: floptst.prg
 * Author....: Gary Smith
 * CIS ID....: 70714,3015
 *
 * This work is based on an original work by Joseph LaCour that
 * was placed in the public domain.  This work is placed in the
 * public domain.
 *
 *  ACKNOWLEDGEMENTS:
 *
 *          PAOLO RAMOZZI FOR HIS WORK IN DBDCHECK FOR SHOWING HOW TO
 *          USE INT 13H.
 *
 *
 * Modification history:
 * ---------------------
 *
 *     Rev 1.4   05 May 1995 03:05:00   TED
 * Gary Smith ported ASM source to Clipper.
 *
 *     Rev 1.3   23 Sep 1991 14:56:42   GLENN
 *  Bug reports from Craig Austin, James Finnal, and Ted Means.  Line 128
 *  had MOV FDRIVE,AL which should have been MOV FDRIVE,BL.  This caused the
 *  function to erroneously use the last drive available instead of the one
 *  specified by the calling process.
 *
 *     Rev 1.2   15 Aug 1991 23:07:48   GLENN
 *  Forest Belt proofread/edited/cleaned up doc
 *
 *     Rev 1.1   11 May 1991 00:21:42   GLENN
 *  File header changed to conform to Toolkit standard.
 */

 */

#include "ftint86.ch"

#DEFINE ERR_WRONG_PARAMETERS  -1
#DEFINE ERR_NO_ERROR          0
#DEFINE ERR_DRIVE_NOT_READY   1
#DEFINE ERR_UNFORMATTED       2
#DEFINE ERR_WRITE_PROTECTED   3
#DEFINE ERR_UNKNOWN           4

#IFDEF FT_TEST
#define CR_LF chr(13)+chr(10)

PROCEDURE MAIN(         ;
                cArg1   ;
              )
   LOCAL nErrCode

   IF ValType( cArg1 ) == "C"
      nErrCode := FT_FLOPTST( Asc( Upper(cArg1) ) - Asc( "A" ) )
      OutStd( "Return Code is "+LTrim(Str(nErrCode)) +CR_LF )
   ELSE
      OutStd( "Usage: floptst cDrive"+CR_LF+" where cDrive is 'A' or 'B' etc..."+CR_LF )
   ENDIF

RETURN

#ENDIF

FUNCTION FT_FLOPTST(                ;     // error code defined by ERR_*
                        nDriveNum_i ;     // letter of floppy drive.
                   )
      LOCAL cBuffer
      LOCAL nErrorCode
      LOCAL nRetCode

      nRetCode := ERR_WRONG_PARAMETERS
      IF ValType( nDriveNum_i ) == "N"

            IF _GetDisketteNum( nDriveNum_i )
                  _ResetDisketteSystem()
                  _ReadBootSector( nDriveNum_i, @cBuffer, @nErrorCode )

                  IF nErrorCode == 0
                        _WriteBootSector( nDriveNum_i, cBuffer, @nErrorCode )
                        DO CASE
                        CASE nErrorCode == 0
                              nRetCode := ERR_NO_ERROR
                        CASE nErrorCode == 3
                              nRetCode := ERR_WRITE_PROTECTED
                        OTHERWISE
                              nRetCode := ERR_UNKNOWN
                        ENDCASE
                  ELSE
                        DO CASE
                        CASE nErrorCode == 128 // 80h
                              nRetCode := ERR_DRIVE_NOT_READY
                        CASE nErrorCode == 2
                              nRetCode := ERR_UNFORMATTED
                        OTHERWISE
                              nRetCode := ERR_UNKNOWN
                        END CASE
                  ENDIF
            ENDIF
      ENDIF

RETURN nRetCode

#define BITS_6AND7      192   // value of byte when bits 6&7 are high

STATIC FUNCTION _GetDisketteNum(          ; // returns false if no floppy drive installed or nDrive_i is invalid
                                    nDrive_i    ; // drive number to query status
                                    )
      LOCAL aRegs[INT86_MAX_REGS]
      LOCAL lRetCode
      LOCAL nByte
      LOCAL nDriveCount

      // ASSERT 0 <= nDrive_i

      lRetCode := .F.
      IF FT_INT86( 1*16+1, aRegs )  // INT for equipment determination
            nByte := lowbyte( aRegs[AX] )
                  // bit 0 indicates floppy drive installed
            IF Int( nByte / 2 ) * 2 != nByte // is it odd i.e. is bit 0 set??
                  // bits 6 & 7 indicate number of floppies installed upto 4.
                  nDriveCount := Asc( FT_BYTEAND( Chr(nByte), chr(BITS_6AND7) ) )
                  IF nDriveCount >= nDrive_i
                        lRetCode := .T.
                  ENDIF
            ENDIF
      ENDIF

RETURN lRetCode

STATIC PROCEDURE _ResetDisketteSystem()
      LOCAL aRegs[INT86_MAX_REGS]

      aRegs[AX] := 0

      FT_INT86( 1*16+3, aRegs )

RETURN

#define BUFFER_SIZEOF_SECTOR  512+1

STATIC FUNCTION _ReadBootSector(          ;
                              nDriveNum,  ;
                              cBuffer_o,  ;
                              nErrCode_o  ;
                              )
      // call BIOS INT 13 for sector read
      LOCAL aRegs[INT86_MAX_REGS]
      LOCAL cBuffer := Space( BUFFER_SIZEOF_SECTOR )
      LOCAL lSuccess
      LOCAL nErrorCode
      LOCAL lCarryFlag

      aRegs[DX] := nDriveNum   // DH = 0 Head 0, DL = drive number
      aRegs[CX] := 1          // CH = 0 track 0, CL=1 sector 1
      aRegs[BX] := REG_ES           // buffer in ES:BX
      aRegs[ES] := cBuffer
      aRegs[AX] := makehi(2)+1      // AH = 02 read , AL=1 read one sector

      lSuccess := _CallInt13hRetry( aRegs, @lCarryFlag, @nErrorCode )

      cBuffer_o := aRegs[ES]
   nErrCode_o := nErrorCode

RETURN lSuccess

STATIC FUNCTION _WriteBootSector(         ;
                              nDriveNum,  ;
                              cBuffer_i,  ;
                              nErrCode_o  ;
                              )
      // call BIOS INT 13 for sector write
      LOCAL aRegs[INT86_MAX_REGS]
      LOCAL lSuccess
      LOCAL nErrorCode
      LOCAL lCarryFlag

      aRegs[DX] := nDriveNum // DH = 0 Head 0 , DL = drive number
      aRegs[CX] := 1          // CH = 0 track 0, CL=1 sector 1
      aRegs[BX] := REG_ES           // buffer in ES:BX
      aRegs[ES] := cBuffer_i
      aRegs[AX] := makehi(3)+1      // AH = 03 write , AL=1 read one sector

      lSuccess := _CallInt13hRetry( aRegs, @lCarryFlag, @nErrorCode )

   nErrCode_o := nErrorCode

RETURN lSuccess

STATIC FUNCTION _CallInt13hRetry(         ;     // logical: did the interrupt succeed?
                                    aRegs_io,   ;     // registers values for INT 13h
                                    lCarrySet_o,      ; // status of carry flag if return code is true.
                                    nDriveStatus_o    ;     // status of drive ( error code )
                                    )
      LOCAL lCarrySet
      LOCAL aRegisters
      LOCAL lSuccess
      LOCAL nInterrupt_c := 1*16+3  // INT 13h
      LOCAL i

      lCarrySet := .F.
      aRegisters := AClone( aRegs_io )
      lSuccess := FT_INT86( nInterrupt_c, aRegisters )
      IF lSuccess
            lCarrySet := carrySet( aRegisters[FLAGS] )
            IF lCarrySet
                  _ResetDisketteSystem()

                  aRegisters := AClone( aRegs_io )
                  FT_INT86( nInterrupt_c, aRegisters )
                  lCarrySet := carrySet( aRegisters[FLAGS] )
                  IF lCarrySet
                        _ResetDisketteSystem()

                        aRegisters := AClone( aRegs_io )
                        FT_INT86( nInterrupt_c, aRegisters )
                        lCarrySet := carrySet( aRegisters[FLAGS] )
                        IF lCarrySet
                              _ResetDisketteSystem()
                        ENDIF
                  ENDIF
            ENDIF
      ENDIF

      FOR i := 1 TO INT86_MAX_REGS
            // pass altered register back up
            aRegs_io[i] := aRegisters[i]
      NEXT // i
      lCarrySet_o := lCarrySet
   nDriveStatus_o := highByte( aRegisters[AX] )

RETURN lSuccess