'PROGRAM - FCBLABEL.BAS

'Microsoft BASIC module for manipulating volume
'labels

'BASIC Version 7.0 users should change the next
'line to use the QBX.BI file

'$INCLUDE: 'QB.BI'
'$INCLUDE: 'FCBLABEL.BI'

TYPE ExtendedFCBRecord
	ExtFCB   AS STRING * 1
	Res1     AS STRING * 5
	Attr     AS STRING * 1
	Drive    AS STRING * 1
	Name1    AS STRING * 11
	Unused1  AS STRING * 5
	Name2    AS STRING * 11
	Unused2  AS STRING * 9
END TYPE

FUNCTION DeleteDiskID% (Drive$)

	DIM EFCB AS ExtendedFCBRecord
	DIM InRegsX AS RegTypeX, OutRegsX AS RegTypeX

	EFCB.ExtFCB = CHR$(&HFF)  'Set EFCB flag
	EFCB.Attr = CHR$(&H8)     'Vol label attribute
	EFCB.Drive = CHR$(ASC(Drive$) - 64)
	EFCB.Name1 = "*.*        "

	InRegsX.ax = &H1300        'Call find first FCB
	InRegsX.ds = VARSEG(EFCB)  'Load DS:DX with
	InRegsX.dx = VARPTR(EFCB)  'address of EFCB
	CALL INTERRUPTX(&H21, InRegsX, OutRegsX)

'Set error codes

	IF Lo(OutRegsX.ax) = 0 THEN     'Successful
		DeleteDiskID = -1 'True
	ELSE
		DeleteDiskID = 0  'False
	END IF

END FUNCTION

FUNCTION GetDiskID$ (Drive$)
	DIM EFCB AS ExtendedFCBRecord
	DIM InRegsX AS RegTypeX, OutRegsX AS RegTypeX

'  Get Address of Data Transfer Area (DTA)

	CALL GetDTAAddr(Segment, Offset)

'  Call the Find First FCB function
'  using the Volume attribute

	EFCB.ExtFCB = CHR$(&HFF)   'Set EFCB flag
	EFCB.Attr = CHR$(&H8)      'Vol label attribute
	EFCB.Drive = CHR$(ASC(Drive$) - 64)
	EFCB.Name1 = "*.*        "
	InRegsX.ax = &H1100        'Call find first FCB
	InRegsX.ds = VARSEG(EFCB)  'Load DS:DX with
	InRegsX.dx = VARPTR(EFCB)  'address of EFCB
	CALL INTERRUPTX(&H21, InRegsX, OutRegsX)

	GetDiskID$ = ""

	IF Lo(OutRegsX.ax) = 0 THEN  'Successful
		VOL$ = ""
		DEF SEG = Segment       'Set Segment to DTA
		FOR I = Offset + 8 TO Offset + 18
			VOL$ = VOL$ + CHR$(PEEK(I))
		NEXT I
		DEF SEG
		GetDiskID$ = VOL$
	END IF
END FUNCTION

SUB GetDTAAddr (Segment, Offset)

	DIM InRegsX AS RegTypeX, OutRegsX AS RegTypeX

	InRegsX.ax = &H2F00
	CALL INTERRUPTX(&H21, InRegsX, OutRegsX)
	Segment = OutRegsX.es   'Return address of DTA
	Offset = OutRegsX.bx    'Segment:Offset format

END SUB

FUNCTION Lo (IntegerVar)
	Lo = IntegerVar MOD 256
END FUNCTION

FUNCTION RenameDiskID_
                (Drive$, OldDiskID$, NewDiskID$)

	DIM EFCB AS ExtendedFCBRecord
	DIM InRegsX AS RegTypeX, OutRegsX AS RegTypeX

'EFCB setup

	EFCB.ExtFCB = CHR$(&HFF) 'Set EFCB flag
	EFCB.Attr = CHR$(&H8)    'Vol label attribute
	EFCB.Drive = CHR$(ASC(Drive$) - 64)

'Rename specific instructions

	L = LEN(OldDiskID$)
	IF L < 11 THEN
		OldDiskID$ = OldDiskID$ + SPACE$(11 - L)
	END IF
	EFCB.Name1 = OldDiskID$

	L = LEN(NewDiskID$)
	IF L < 11 THEN
		NewDiskID$ = NewDiskID$ + SPACE$(11 - L)
	END IF
	EFCB.Name2 = NewDiskID$

'  Call Service 17H to RENAME a volume label

	InRegsX.ax = &H1700        'Call find first FCB
	InRegsX.ds = VARSEG(EFCB)  'Load DS:DX with
	InRegsX.dx = VARPTR(EFCB)  'address of EFCB
	CALL INTERRUPTX(&H21, InRegsX, OutRegsX)

'Set error codes

	IF Lo(OutRegsX.ax) = 0 THEN     'Successful
		RenameDiskID = -1 'True
	ELSE
		RenameDiskID = 0  'False
	END IF

END FUNCTION

FUNCTION SetDiskID (Drive$, VolumeName$)

	DIM EFCB AS ExtendedFCBRecord
	DIM InRegsX AS RegTypeX, OutRegsX AS RegTypeX

	CALL GetDTAAddr(Segment, Offset)

'  Call the Find First FCB function
'  using the Volume attribute

	EFCB.ExtFCB = CHR$(&HFF) 'Set EFCB flag
	EFCB.Attr = CHR$(&H8)    'Vol label attribute
	EFCB.Drive = CHR$(ASC(Drive$) - 64)
	L = LEN(VolumeName$)
	IF L < 11 THEN
		VolumeName$ = VolumeName$ + SPACE$(11 - L)
	END IF
	EFCB.Name1 = VolumeName$
	InRegsX.ax = &H1600        'Call find first FCB
	InRegsX.ds = VARSEG(EFCB)  'Load DS:DX with
	InRegsX.dx = VARPTR(EFCB)  'address of EFCB
	CALL INTERRUPTX(&H21, InRegsX, OutRegsX)

	IF Lo(OutRegsX.ax) = 0 THEN     'Successful
		SetDiskID = -1 'True
	ELSE
		SetDiskID = 0  'False
	END IF
END FUNCTION