;::::::::::::::::::::::::::::::::::::::::::::******************************
;	  Floppy Disk Routines		     ***** Hardware Dependent *****
;     - D-X Designs Pty Ltd P112 -	     ******************************
;
; 1.3 - 26 Aug 01 - Cleaned up for GPL Release.				HFB
; 1.2c- 12 May 97 - Cleaned up source, modified STSIZE Code (again).	HFB
; 1.2b- 22 Apr 97 - Changed 5.25" Hi/Lo Speed controls.			HFB
; 1.0a- 23 Mar 97 - (test) fixes.					HFB
; 1.0 - 13 Aug 96 - Initial Release for P112 from YASMIO.		HFB
;::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
; Floppy Units are accessed on the P112 using the on-board SMC FDC37C665.
; An optional assembly flag controls whether Polled or DMA-controlled IO is
; used in operation.  The DMA mode does not use any Interrupts in this
; preliminary version, but instead polls the INT1* line as Bit 6 on Port C
; of the Z182.
; This software uses the following registers:

;    0DE	- Port C, Bit 6=INT1*, Bit 7=INT2*	(DRC)

;    090	- Configuration Control Port	(CFCNTL)
;    091	- Configuration Data Port	(CFDATA)

; The Chip configuration must be altered only to change the polarity on the
; Density signal applied to Pin 2 on the Floppy Connectors.  Optional code
; which may be used forces this lead Hi/Lo as required for different formats
; using two bits of Configuration Register #5.

CR5	EQU	5		; FDC/IDE setups
	;Bit 7 6 5 4 3 2 1 0
	;    | | | | | +-+-+-  unused
	;    | | | +-+------- 00 = Density Normal (tracks Data Rate)
	;    | | |	      01 = (reserved), 10 = Force "1", 11 = Force "0"
	;    +-+-+-----------  unused

;    092	- Drive Control Register	(Write Only)
;	7 6 5 4 3 2 1 0
;	| | | | | | +-+-- Drive (00=0, 01=1, 10=2, 11=3)
;	| | | | | +------ 1 = Normal Opn, 0 = Reset Controller
;	| | | | +-------- 1 = Enable DMA Pins, 0 = Disable DRQ,DAK,INT pins
;	| | | +---------- 1 = Enable Drive 0 Motor
;	| | +------------ 1 = Enable Drive 1 Motor
;	| +-------------- 1 = Enable Drive 2 Motor
;	+---------------- 1 = Enable Drive 3 Motor
;    093	-  (Not Used)
;    094	- Data-Rate Select (Write) / Main Status Register (Read)
;	7 6 5 4 3 2 1 0				(Write)

;	7 6 5 4 3 2 1 0				(Read)
;	| | | | +-+-+-+-- Drives Seeking (0=B0 Set, 1=B1 Set,.. 3=B3 Set)
;	| | | +---------- 1 = Command In Progress, 0 = Command Ended
;	| | +------------ 1 = Non-DMA Execution,   0 = DMA Execution
;	| +-------------- 1 = Read,		   0 = Write
;	+---------------- 1 = Request for Master,  0 = Internal Execution
;
;    095	- Data/Command Register		(Read/Write)
;				(Byte Writes/Reads)
;    096	-  (Not Used)
;    097	- Data Rate Register (Write) / Disk Changed Bit (Read)
;	7 6 5 4 3 2 1 0				(Write)
;	| | | | | | +-+-- 00=500 kb/s, RPM/LC Hi, 01=250/300 kb/s (RPM/LC Lo)
;	| | | | | |	  10=250 kb/s, RPM/LC Lo, 11=1000 kb/s (RPM/LC Hi/Lo)
;	+-+-+-+-+-+------  (Not Used)
;
;	7 6 5 4 3 2 1 0				(Read)
;	| +-+-+-+-+-+-+-- (Tri-State, used for HD Controller)
;	+---------------- 1 = Disk Changed  (latched complement of DSKCHG inp)
;
;    0A0	- DMA I/O Select Port (DMA configuration Only)

	  IF  BANKED
	COMMON	/BANK2/
	  ELSE
	CSEG
	  ENDIF

;:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
; STMODE  (Function 0) - Set the FDC mode for Read/Write operations.
;
; Enter	:  A = Single-Density Flag (0 = Double Dens, 0FFH = Single Dens)
; Return: Nothing
; Uses	: AF		All other Registers Preserved/Not Affected
;
; Assumes STSIZE and STSECT called first
;:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::

STMODE:	PUSH	BC		; Save Regs
	PUSH	HL
	CPL			; Flip Bits so 1=MFM, 0=FM
	AND	01000000B	;  keep only bit of interest
	LD	(MODE),A	; Set MT, MF, SK for Commands
	LD	B,A		;  (for later)
	LD	A,(DRVSIZ)
	DEC	A		; becomes: 8"=0, 5"=1, 3"=2
	LD	L,2		; (prepare for 8")
	JR	Z,STMOD2	; ..jump if 8" (same as HD)
	DEC	L		; Else set  to 3/5" Low Speed (1)
	LD	A,(DRVSPD)
	OR	A		; Low Speed?
	JR	Z,STMOD2	; ..jump if So
	INC	L		; Else bump to 2 for Hi-Speed
	LD	A,(DRVSIZ)
	SUB	2		; 5.25" Hi-Density?
	JR	Z,STMOD2	; ..jump if So pointing to 8"/5.25"HD
	LD	L,8+GAP3HD-FM5G3 ; Else Offset to 3.5" HD Gaps
	JR	STMOD4		; ..and set SecSize

STMOD2:	BIT	6,B		; MFM Set?
	JR	Z,STMOD3	; ..jump if Not
	SCF			; Else Set Carry if MFM
STMOD3:	RL	L		; Shift into LSB, Size * 2
	ADD	HL,HL
	ADD	HL,HL		; Size * 8, MFM * 4 (only 1 matters)
STMOD4:	LD	A,(RSZ)
	LD	(NBYTS),A	;  save in Comnd Blk
	OR	A
	PUSH	AF
	ADD	A,L		; Add Sector Size to computation
	LD	L,A		;  and Store
	POP	AF
	LD	A,129		; (Prepare default)
	JR	Z,STMOD1	; ..jump if 128-byte Sectors (DTL=128)
	XOR	A		; Else DTL is 0FFH (0-->FF)
STMOD1:	DEC	A		; Correct DTL Value
	LD	(DTL),A		;  set
	LD	A,L		; Xfer index to A
	LD	HL,FM5G3-8	; No low speed on 8"
	CALL	ADDAHL		; Index into gap 3 table
	LD	A,(HL)
	LD	(GPL),A		;  store Gap Length
	POP	HL
	POP	BC
	RET

;:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
; STSIZE  (Function 1) - Set Drive Size (3.5", 5.25", 8"), Drive Speed
;  (High/Low) Capability, and a Boolean flag for whether Motor Control is
;  needed by the Drive.
;
; Enter :  A = Hi Speed Flag ( 0 = Normal, 0FFH = High Speed Capable)
;	   D = Motor Flag (0 = No Motor Control, 0FFH = Motor needed)
;	   E = Drive Size (0 = Hard, 001 = 8", 010 = 5.25", 011 = 3.5")
; Return: Nothing
; Uses	: AF		All other Registers Preserved/Not Affected
;
; Assumes STHDRV Called Previously.   Call before calling STMODE.
;:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::

STSIZE:	LD	(DRVSPD),A	; Save Drive Speed Flag
	OR	A		;  (set flag, 0=Normal, FF=Hi-Speed/Density)
	LD	A,E
	LD	(DRVSIZ),A	;   Save Drive Size Byte
	LD	A,D
	LD	(FDMOT),A	;     Set Drive Motor Needed flag
	PUSH	DE		; (Save Regs)
	LD	A,00000000B	; (Preset Hi 500 kbps, 3.5 & 5.25" Rate)
	JR	NZ,STSIZ2	; ..jump if Hi-Density/Speed to Set
	DEC	E
	DEC	E		; 5.25" (010B -> 00)?
	LD	A,00000010B	;  (Prepare for 250 kbps)
	JR	NZ,STSIZ2	; ..jump if Not 5.25" w/Rate Set
	PUSH	HL
	LD	A,(HDR)		; Else use a routine from FLOPPY.Z80 to
	CALL	PHYSCL		;   point to Physical Drive Byte (ICFG-xx)
	BIT	6,(HL)		; Hi-Density capable?
	POP	HL
	LD	A,00000010B	;  (Prepare for 250 kbps)
	JR	Z,STSIZ2	; ..jump if No
	LD	A,00000001B	; Else set to 300 kbps (@360 rpm = 250kbps)
STSIZ2:	OUT	(DRR),A		; Set Rate in FDC Reg
	LD	D,A		;   preserve Rate bits
	IN0	A,(1FH)		; Read Cntrl Reg (B7=1 if Hi Speed)
	RLA			;  Speed to Bit Carry..Turbo?
	LD	A,(SPEED)	;   (Get Processor Rate in MHz)
	JR	C,STSIZ8	;  ..jump if Turbo for longer delay
	SRL	A		;  Else divide rate by 2
STSIZ8:	INC	D
	DEC	D		; 500 kb/s (Hi-Speed) Rate (D=0)?
	JR	NZ,STSIZ9	; ..jump if Not
	LD	A,1		;  Else minimum delay for "High-Speed"
STSIZ9:	LD	(DLYCNT),A	;   save delay count
	POP	DE
	RET

;:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
; STHDRV  (Function 2) - Set Head and Drive for Disk Operations.
;
; Enter :  A = Unit # in D0-D1, Head in D2
; Return: Nothing
; Uses	: AF		All other Registers Preserved/Not Affected
;:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::

STHDRV:	LD	(HDR),A		; Save the Combined Head/Drive Byte
	PUSH	BC		;  Save Regs
	LD	B,A		;   and the HDR byte
	SRL	A		; Move
	SRL	A		;  Head to B0
	LD	(HD),A		;   and Save
	LD	A,(ACTIVE)	; Get current Activation Byte
	  IF  FDDMA
	AND	11111000B	;  keep only motors and DMA Bit
	  ELSE
	AND	11110000B	;  If Polled, keep only motors
	  ENDIF
	OR	B		;   add drive bit
	POP	BC		; Restore Regs
	JP	ACTIV8		; ..exit saving new byte and activating FDC

;:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
; STSECT  (Function 3) - Set Sector Number, Sector Size and Last Sector #
;
; Enter :  A = Physical Sector Number
;	   D = Sector Size (0=128, 1=256, 2=512, 3=1024)
;	   E = Last Physical Sector # on Side
; Return: Nothing
; Uses  : AF		All other Registers Preserved/Not Affected
;:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::

STSECT:	LD	(SECT),A	; Set Sector Number
	LD	A,D		; Get sector size
	LD	(RSZ),A		;  save for commands
	LD	A,E		; Get last sector number
	LD	(EOT),A		;   save in Command Block
	RET

;:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
; SPEC  (Function 4) - Do a Specify Command, setting Step Rate and Head
;  Load/Unload Time.  Values are rounded up if not even increments.
;
; Enter :  A = Step Rate (in mS;  Bit 7 = 1 for 8" drive
;	   D = Head Unload Time (in mS)
;	   E = Head Load Time (in mS)
; Return: Nothing
; Uses	: AF		All other Registers Preserved/Not Affected
;
; Assumes STSIZE called previously to set DRVSPD variable.
;:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::

SPEC:	PUSH	BC		; Save Regs
	PUSH	DE
	AND	7FH		;  Strip 8" Bit from Step Rate

; At 250 kb/s MFM (125 kb/s FM), the times are doubled, so we must
;  Divide the delays by two, else leave alone for 500 kb/s

	LD	B,A		; Save the Step Rate
	LD	A,(DRVSPD)	; Get Speed (Data Rate)
	OR	A		; High Speed?
	LD	A,B		;  (restore Step Rate)
	JR	NZ,SPEC0	; ..jump if 500 kb/s (High Density)

	SRL	A		; Divide Step Rate by 2
	ADC	A,0		;  round Up for partial
	SRL	D		; Divide Head Unload Time by 2
	JR	NC,SPEC11	; ..jump if No Rounding Corr.
	INC	D
SPEC11:	SRL	E		; Divide Head Load Time by 2
	JR	NC,SPEC0	; ..jump if No Rounding Corr.
	INC	E		; Else Round
SPEC0:	NEG			; Get 2's Complement of Step Rate
	AND	0FH		;  mask
	LD	B,A		;   (save)
	LD	A,D		; Get Head Unload Time in mS
	ADD	A,0FH		;   force Rounding up
	JR	C,SPEC00	; ..jump if Overflow to Max
	AND	0F0H		; Keep Time MOD 16
	JR	NZ,SPEC3	; ..jump if Not Zero
SPEC00:	LD	A,0F0H		; Else go to Maximum allowed
SPEC3:	OR	B		; Add in Step Rate
	RLCA
	RLCA
	RLCA
	RLCA			; Swap Nibbles
	LD	D,A		;  put combined byte back in D
	CALL	WRDY		; Wait for RQM (hope DIO is Low!), retain Ints
	LD	A,03H		; Do an FDC Specify Command
	OUT	(DR),A
	CALL	WRDY
	LD	A,D		;  first Rate Byte (Step Rate, HUT)
	OUT	(DR),A
	CALL	WRDY
	LD	A,E		; Get Head Load Time
	ADD	A,A		;  Shift rate to B7..1
	  IF  NOT FDDMA		;   (Bit 0 = 0 for DMA)
	OR	1		;    Insure Non-DMA Operation
	  ENDIF
	OUT	(DR),A
	POP	DE		;  Restore Regs
	POP	BC
	RET

;:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
; RECAL  (Function 5) - Recalibrate Drive (moves heads to track 0).
;
; Enter	: Nothing
; Return:  A = 0 if Ok, NZ if Error.  Flags reflect A
; Uses	: AF		All other Registers Preserved/Not Affected
;
; NOTE: BC Must be preserved by this routine.
; Assumes STHDRV, SPEC, STSIZE and STMODE called first.
;:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::

RECAL:	LD	A,3		; Give this 3 chances to Home
RECAL1:	LD	(RETRYS),A
	PUSH	BC		; Save needed regs
	LD	BC,2*256+7	; Two bytes, Recalibrate = 7
	PUSH	HL
	CALL	FDCMD		;  execute Recalibrate
	POP	HL
	  IF  NOT FDDMA
	CALL	FDCDN		; Clear Pending Ints, Wait for Seek Complete
	AND	00010000B	; Homed?  (B4=1 if No Trk0 found)
	  ENDIF
	POP	BC		;   (restore regs)
	JR	Z,RECOK		; ..jump to Store if Ok

	LD	A,(RETRYS)
	DEC	A		; Any trys left?
	JR	NZ,RECAL1	; ..loop if So
	DEC	A		; Else set Error Flag (0-->FF)
	RET

RECOK:	PUSH	HL		; Save Regs
	CALL	IDXTRK		; Point to Current Drive in Track Array
	XOR	A		;  get a Zero
	LD	(HL),A		;   set Drive's Trk to 0
	POP	HL		; Restore regs
	RET			;   and return

;:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
; SEEK   (Function 6) - Set the Track for disk operations and seek to it.
;
; Enter :  A = Desired Track Number
;	   D = Verify flag (0=No, FF=Yes)
;	   E = Double-step Flag (E <> 0 for Double-step)
; Return:  A = 0, Zero Flag Set (Z) if Ok, A <> 0 Zero Clear (NZ) if Error
; Uses  : AF		All other Registers Preserved/Not Affected
;
; Assumes STHDRV, SPEC, STSIZE and STMODE are called first.
;:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::

SEEK:	LD	(TTRK),A	; Save Track to Seek
	PUSH	HL		; Save Regs used here
	PUSH	DE
	PUSH	BC

	CALL	IDXTRK		; Point to Current Trk for Selected Drive
	CP	(HL)		; Is desired Track same as last logged?
	JR	NZ,SEEKNV	; ..jump if Not Same
	INC	D		; Else Set to No Verify (FF->0)
SEEKNV:	LD	A,E		; Get Double-step flag
	LD	(STEP2),A	; ..and save locally

	LD	A,(MXRTRY)	; Get the maximum Count
SEEK1:	LD	(RETRYS),A	;   save remaining Retry Count
	LD	A,E
	OR	A		; Double Step?
	LD	A,(TTRK)	; Restore Track #
	JR	Z,SEEK2		; ..jump if No Double Step
	ADD	A,A		; Else double Track #
SEEK2:	LD	(TRK),A		; Save the Track # in Comnd Block
	LD	BC,3*256+0FH	;   (3-byte Seek Command = 0FH)
	PUSH	HL
	CALL	FDCMD		; Execute the Seek
	POP	HL
	  IF  FDDMA
	OR	A		;  Insure flags set
	  ELSE
	CALL	FDCDN		; Clear Pending Int, wait for Seek Complete
	AND	01000000B	; Set NZ if Abnormal Termination
	  ENDIF
	JR	NZ,SEEKER	; ..jump if Error Seeking
	INC	D		; Are we Verifying (FF -> 0)?
	DEC	D		;    (Correct for Test, 0 -> FF)
	CALL	NZ,READID	;   Read next ID Mark if So
	JR	Z,SEEKX		; ..exit if Ok

SEEKER:	LD	A,(RETRYS)	; Else get trys remaining
	DEC	A		; Any left (80-track could need two)?
	JR	NZ,SEEK1	; ..loop to try again if More
	DEC	A		; Else set Error Flag (0->FF)
SEEKX:	LD	E,A		;  (Save status byte)
	LD	A,(TTRK)
	LD	(TRK),A		; Restore "Real" Track Number
	JR	NZ,SEEKXX	; ..jump if Error
	LD	(HL),A		;  Else update Track in Index
SEEKXX:	LD	A,E		; Restore Status
	OR	A		;  set flags
	POP	BC		; Restore Regs
	POP	DE
	POP	HL
	RET

;.........................................................................
; Actual Read or Write

ACTRW:	LD	HL,(ACTDMA)	; Get actual DMA Addr
	LD	A,(RDOP)
	OR	A		; Read operation?
	JR	Z,SWRITE	; No, must be Write

;:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
; SREAD  (Function 7) - Read a Sector from the Floppy Disk.  The Mode,
;  Head/Drive, Track, and Sector must have already been set.
;
; Enter : HL --> Read Buffer
; Return:  A = 0, Zero Set (Z) if Ok, A <> 0, Zero Clear (NZ) if Error.
; Uses	: AF,HL.	All other Registers Preserved/Not Affected
;
; Assumes STMODE, STHDRV, STSECT, SPEC and SEEK Called First.
;:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::

SREAD:	LD	A,0110B		; Load 765 Read Command (06H)
	  IF  FDDMA
	PUSH	AF		; Save Command
	LD	A,11001101B	;  Set DMA Direction
		; |||||||+-  ?
		; ||||||+-- MOD = Cycle Steal (ignored in I/O)
		; ||||++--- Source = I/O (fixed)
		; ||++----- Dest = Memory (Auto-Inc)
		; ++-------  ?
	  ENDIF
	JR	RW		; ..and continue below

;:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
; SWRITE  (Function 8) - Write a Sector to the Floppy Disk.  The Mode,
;  Head/Drive, Track, and Sector must have already been set.
;
; Enter : HL --> Write Buffer
; Return:  A = 0, Zero Flag Set (Z) if Ok, A <> 0 Zero Clear (NZ) if Errors
; Uses	: AF,HL.	All other registers Preserved/Not Affected.
; Assumes STMODE, STHDRV, STSECT, SPEC and SEEK Called First.
;:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::

SWRITE:	LD	A,0101B		; Load 765 Write Command (05H)
	  IF  FDDMA
	PUSH	AF		; Save Command
	LD	A,11110001B	;  Set DMA Direction
		; |||||||+-  ?
		; ||||||+-- MOD = Cycle Steal (ignored in I/O)
		; ||||++--- Source = Memory (Auto-Inc)
		; ||++----- Dest = I/O (fixed)
		; ++-------  ?
RW:	OUT0	(DMODE),A	; Set DMA Channel #0 direction
	POP	AF		;  restore Rd/Wr Comnd
	  ELSE
RW:
	  ENDIF		;fddma
	PUSH	BC		; Save Regs
	PUSH	DE
	  IF  FDDMA
	CALL	SFDMA		; Set DMA Transfer Regs
	LD	HL,MODE		; Pt to Mode Flag
	OR	(HL)		;  add to Command
	  ELSE
	LD	C,A		;  (Save Command)
	LD	A,(MODE)	; Get Mode Flag
	OR	C		;  add Read/Write Command to Mode Flag
	  ENDIF		;fddma
	LD	C,A		;   to Reg
	LD	B,9		; Read/Write Comnds are 9 bytes

	LD	A,(TSBSCF)	; Get Special Format Flag
	OR	A		; Special?
	JR	NZ,RW0		; ..jump if Not
	LD	(HD),A		;  Else Side 1 coded with Hd # 0
RW0:	LD	A,(RSZ)		; Get Sector Size Code
	LD	(NBYTS),A	;   and Set in Comnd Blk

	LD	A,(EOT)		; Get Last Sctr #
	PUSH	AF		;  (save for Exit)
	LD	A,(SECT)	; Get Desired Sector #
	LD	(EOT),A		;  make last to Read only one Sector

	PUSH	HL
	CALL	FDCMD		; Execute Read/Write
	POP	HL

	POP	AF		; Restore Last Sctr #
	LD	(EOT),A		;  to Comnd Blk
	LD	A,(ST1)		; Get Status Reg 1
	AND	34H		; Return Any Error Bits
	POP	DE		; Restore Regs
	POP	BC
	RET

;:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
; READID  (Function 9) - Read the first Valid Address Mark on a track.
;
; Enter : Nothing
; Return:  A = 0 if Ok, NZ if Error.  Flags reflect A
; Uses	: AF		All other Registers Preserved/Not Affected
;
; Assumes STHDRV, SPEC, STSIZE and STMODE called first.
;:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::

READID:	LD	A,(MODE)	; Get Command byte from block
	OR	0AH		;  or in Command
	PUSH	BC		; Save regs
	LD	B,2		;  two bytes in ReadID Command
	LD	C,A		;   move Command to C
	PUSH	HL
	CALL	FDCMD		; Activate Controller
	POP	HL
	LD	A,(ST1)		; Get Status Reg 1
	AND	25H		;  Keep only Error Bits
	POP	BC		; Restore regs
	RET			; ..and quit

;:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
; RETDST (Function 10) - Return the status of a drive.
;  This routine reports a "765" Controller type instead of actual number.
;
; Enter : Nothing
; Return:  A = Status byte
;	  BC = 765 (FDC Controller Type)
;	  HL = Address of Status Byte
; Uses  : AF,BC,HL		All other Registers Preserved/Not Affected
;
; Assumes STHDRV called first
;:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::

RETDST:
	  IF  FDDMA
	CALL	WRDY		; Wait for RQM to be Set
	LD	A,0100B		; Load Return Drive Status Command (04H)
	OUT0	(DR),A		;  send to FDC
	CALL	WRDY
	LD	A,(HDR)		;   Get Drive and Head
	OUT	(DR),A		;    send it too
	CALL	FDCIN0		; Read Stat at Command End
	  ELSE
	LD	BC,2*256+04H	; 2-byte Return Drive Status Command
	CALL	FDCMD
	  ENDIF		;fddma
	LD	HL,ST0		; Point to Status Byte (Reg 3 contents)
	LD	A,(HL)		;  fetch it
	LD	BC,765		;   load Controller ID
	RET

;:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
; FMTTRK  (Function 11) - Format a complete track on one side of a Floppy
;  Disk.  The Mode, Head/Drive, Track, and Sector must have been set.
;
; NOTE: The contents of the Format Data Block varies between controllers,
;  so RETDST should be called to determine the controller type before
;  setting up data structures.
;
; Enter :  D = Formatting Sctrs/Track value
;	   E = Formatting Gap 3 Byte Count
;	  HL = Pointer to Controller-dependent Format Data block
; Return:  A = 0, Zero Flag Set (Z) if Ok, A <> 0 Zero Clear (NZ) if Errors
; Uses  : All Primary Registers
;:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::

FMTTRK:	PUSH	DE		; Save for Later
	  IF  FDDMA
	LD	A,11110001B	;  Set DMA Direction
		; |||||||+-  ?
		; ||||||+-- MOD = Cycle Steal (ignored in I/O)
		; ||||++--- Source = Memory (Auto-Inc)
		; ||++----- Dest = I/O (fixed)
		; ++-------  ?
	OUT0	(DMODE),A	; Set DMA Channel #0 direction
	LD	A,(TPABNK)	; Format Data comes from TPA Bank
	   IF  BANKED
	RL	H		; Eliminate the MSB of DMA Addr
	ADC	A,0		;  offset bank # by 32k banks
	RRA			;   shift Bank LSB to Carry
	RR	H		; Move Bank # LSB (Carry) to Address MSB
	   ENDIF	;banked
	LD	(FDMAB+2),A	; Set the Bank Value
	LD	(FDMAB),HL	;  and DMA Address for Bank in DMA Comnd Block
	LD	HL,_DMA		; Get DMA IO Port addr
	LD	(FDMAB+3),HL	;  place in DMA Comnd Block
	XOR	A
	LD	(FDMAB+5),A	;   and Null out rest of Dest
	CALL	STFDMA		; Set DMA for Format

	  ELSE		;~fddma
	   IF  BANKED
	LD	BC,(TPABNK)	; Get Source and Dest Banks
	CALL	XMOVE		;   set them up
	   ENDIF
	LD	DE,HSTBUF	; Move the data to Host Buffer
	LD	BC,256		; Two Sector's worth should be enough
	CALL	MOVE		;   and move it
	POP	DE		; Restore SPT (D) and Gap3 (E)
	  ENDIF		;~fddma
	LD	A,(MODE)
	OR	1101B		;  set command to Format
	LD	C,A		;   and place in Reg
	LD	HL,TRK
	LD	A,(RSZ)
	LD	(HL),A		; Place values in Command Block
	INC	HL
	LD	(HL),D
	INC	HL
	LD	(HL),E
	INC	HL
	LD	(HL),0E5H	; Set byte to write as Data
	LD	B,6		; Six bytes in Format Command
	  IF  NOT FDDMA
	LD	HL,HSTBUF
	  ENDIF
	CALL	FDCMD		; Execute !
	LD	A,(ST1)		;  Get Status
	AND	92H		;   Return Error bits in A
	RET

;=============================================================================
; FDCMD - Send Command to FDC
; Enter:  B = # of Bytes in Command, C = Command Byte
;	 HL -> Buffer for Read/Write Data (If Needed)
; Exit : AF = Status byte
; Uses : AF,BC

FDCMD:	PUSH	HL		;   save regs
	CALL	MOTOR		; Insure motors are On
	LD	HL,COMND	; Point to Command Block
	LD	(HL),C		;  command passed in C
	LD	C,DR		;   Set Data Port Addr
OTLOOP:	CALL	WRDY		; Wait for RQM (hoping DIO is Low) (No Ints)
	OUTI			; Output Command bytes to FDC
	JR	NZ,OTLOOP	; ..loop til all bytes sent

	POP	HL		; Restore Transfer Addr
	DI			; No Ints during IO to avoid data loss
FDCI1:
	  IF  FDDMA
	CALL	FDCINT		; "Call" the Interrupt handler instead of Int
	RET	C		; ..quit if Timeout Error (C, A=FF)
	LD	A,(ST0)		; Else get first byte of Status
	AND	0C0H		;  check for Normal termination
	RET			; ..return w/Error Flags set
	  ELSE
	CALL	WRDY
	BIT	5,A		; In Execution Phase?
	JR	Z,FDCRES	; ..jump if Not to check result
	BIT	6,A		; Write?
	JR	NZ,FDCI2	; ..jump if Not to Read
	OUTI			; Else Write a Byte from (HL) to (C)
	JR	FDCI1		;   and check for next

FDCI2:	INI			; Read a byte from (C) to (HL)
	JR	FDCI1		;   and check for next

; Enter the Result Phase of the Command.  Gather returned bytes

FDCRES:	EI			; Interrupts Ok now if in Result Phase
	LD	HL,ST0		; Point to Status Result area
ISGO:	CALL	WRDY
	BIT	4,A		; End of Status/Result?
	RET	Z		; ..return if So
	BIT	6,A		; Another byte Ready?
	RET	Z		; ..return if Not
	INI			; Else Read Result/Status Byte
	JR	ISGO		; ..loop for next

;.....
; Check for Proper Termination of Seek/Recalibrate Actions by
;  executing a Check Interrupt Command returning ST0 in A.

FDCDN:	PUSH	HL		; Don't alter regs
	EI			;  (Ints Ok Now)
FDCDN0:	CALL	WRDY		; Ready? (leave Ints alone)
	LD	A,08H		; Else Issue Sense Interrupt Status Comnd
	OUT0	(DR),A
	CALL	WRDY
	IN0	A,(DR)		; Get first Result Byte (ST0)
	LD	L,A
	CP	80H		; Invalid Command?
	JR	Z,FDCDN0	; ..jump to exit if So
	CALL	WRDY
	IN0	A,(DR)		; Read Second Result Byte (Trk #)
	LD	A,L
	BIT	5,A		; Command Complete?
	JR	Z,FDCDN0	; ..loop if Not
	POP	HL
	RET
	  ENDIF		;~fddma

;:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
; MOTOR CONTROL.  This routine performs final selection of the drive control
;  latch and determines if the Motors are already spinning.  If they are off
;  and Motor control is needed, then the Motors are activated and the spinup
;  delay time in tenths-of-seconds is performed before returning.
;
; Enter : Command byte in A
; Return: Head Delay bit set in Command in A if needed
; Uses  : None.  All Registers Preserved/Not Affected

MOTOR:	PUSH	AF		; Save Reg
	LD	A,(FDMOT)
	OR	A		; Need Motor?
	JR	Z,MOTORX	; ..jump to exit if Not

	LD	A,(MOTIM)	; Get remaining seconds
	OR	A		; Already On?
	LD	A,(MONTIM)	;  (get Default On Time)
	LD	(MOTIM),A	;   always reset
	EI			; Insure Ints are Active
	JR	NZ,MOTORX	; ..exit if Motors On..they will stay On

	LD	A,(HDR)		; Get current Drive
	  IF  FDDMA
	OR	11111100B	;   Set All Motors and DMA On, Cntrlr Active
	  ELSE
	OR	11110100B	;   Set All Motors On, DMA Off, Cntrlr Active
	  ENDIF
	CALL	ACTIV8		;     Do It!
	LD	A,(SPINUP)	; Get Spinup Time
	LD	(MTM),A		;  to GP Counter
MOTOLP:	LD	A,(MTM)
	OR	A		; Up to Speed?
	JR	NZ,MOTOLP	; ..loop if Not
MOTORX:	POP	AF		; Restore Reg
	RET

;:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
; Hardware-Dependent Host Read/Write Routine linked to from FLOPPY module.
;  This routine Reads/Writes data from HSTBUF trying up to MXRTRY times
;  before giving up.  If an error occurs after the next-to-last try, the
;  heads are homed to force a re-seek.
;
; Enter:  (RDOP Set for desired operation)
; Exit :  A = 0, Zero Set if Ok, A <> 0, Zero Reset if Errors
; Uses : AF,HL
;
; RDOP is set to 1 for Read, 0 for Write, TTRK set with desired Track
;  number, STHDRV, STSECT, STMODE, SPEC all called previously.
;:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::

FHDRW:	LD	HL,HSTBUF	; Point to the host buffer
	LD	(ACTDMA),HL	;  and set Memory Pointer

	LD	(FRWSTK),SP
	LD	SP,FRWSTK	; Use Local Stack
	LD	A,(MXRTRY)	; Get the maximum retry count
RWF2:	LD	(RWRTRY),A
	PUSH	DE		;  (Save Regs)
	LD	A,(STEP2)	; Get double-Step flag
	LD	E,A
	LD	D,0FFH		;  (Verify needed)
	LD	A,(TTRK)	;   and track
	CALL	SEEK		; Try to seek to the desired track
	POP	DE		;  (Restore Regs)
	CALL	Z,ACTRW		; Call R/W if Seek succeeded
	LD	(ERFLAG),A	;  Save error code in any case
	JR	Z,FHDRX		; ..jump to return if No Errors

	LD	A,(RWRTRY)	; Get retry count
	CP	2		; Are we on Next to last try?
	CALL	Z,RECAL		;  Return to Track 0 if so
	LD	A,(RWRTRY)	;   and re-fetch try count
	DEC	A		; Do we have more retries left?
	JR	NZ,RWF2		; ..jump to try again if more tries remain

	CALL	ERROR		; Else print Error Bios Message
FHDRX:	LD	SP,(FRWSTK)	;  Restore Entry Stack
	RET			;   and Exit

;:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
; Gap 3 Length Table
; Index is:  ((Drive_Factor * 8) + (MFM * 4) + RSZ) - 8
;	Where Drive_Factor is based on Size and Speed as:
;		5.25"/3.5" Low Speed  = 1
;		8" (Speed Ignored)    = 2
;	3.5" High-Density Disks use special GAP3 Table, while 5.25" High-
;		Density disks use 8" DD GAP3 values.
;:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
; 5.25"/3.5" Single-Density GAP3.		300 rpm, 125 kbps, FM

FM5G3:	DEFB	7		; 128
	DEFB	5		; 256
	DEFB	20		; 512
	DEFB	27		; 1024

; 5.25"/3.5" Double-Density GAP3.		300 rpm, 250 kbps, MFM

	DEFB	0		; 128
	DEFB	9		; 256
	DEFB	13		; 512
	DEFB	27		; 1024

; 8" Single-Density / 5.25" High-Speed GAP3.	360 rpm, 250 kbps, FM

	DEFB	7		; 128
	DEFB	5		; 256
	DEFB	27		; 512
	DEFB	27		; 1024

; 8" Double-Density / 5.25" High-Speed GAP3.	360 rpm, 500 kbps, MFM

GAP5HD:	DEFB	0		; 128
	DEFB	15		; 256
	DEFB	11		; 512
	DEFB	17		; 1024

; 3.5" Hi-Density GAP3.				300 rpm, 500 kbps, MFM

GAP3HD:	DEFB	0		; 128
	DEFB	27		; 256
	DEFB	27		; 512
	DEFB	17		; 1024		(27 if 10 spt)

;:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
; Error Printing Routine.  This routine prints Error messages from the
;  High-level Sector Read/Write routine when detected based on various
;  parameters in the BIOS.
; Entering a Control-C after the message will cause a warm boot, anything
;  else will ignore the error and return status to the caller.
;:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::

ERROR:
	  IF  BIOERM
	PUSH	BC
	PUSH	DE		
	CALL	PRINT
	DEFB	BELL,CR,LF
	DEFC	'FDC Error, U'
	LD	A,(HDR)		; Get unit number
	AND	3
	CALL	PDEC		; ..in decimal
	CALL	PRINT
	DEFC	' '

	LD	A,(COMND)	; Get the command byte
	AND	3FH		; Else Mask Command
	CP	0FH		; 765 type Seek?
	JR	NZ,ERR0		; ..jump if Not

	CALL	PRINT
	DEFC	'Seek'
	JR	ERR4

ERR0:	CP	05H		; 765 type Write?
	JR	NZ,ERR1		; ..jump if  Not
	CALL	PRINT
	DEFC	'Wr'
	JR	ERR4

ERR1:	CP	06H		; 765 type Read?
	JR	NZ,ERR2		; ..jump if Not
	CALL	PRINT
	DEFC	'Rd'
	JR	ERR4

ERR2:	CALL	PRINT
	DEFC	'Comnd = '
	LD	A,(COMND)
	CALL	PHEX

ERR4:	CALL	PRINT
	DEFC	', '
	LD	HL,ST0		; Point to Status Bytes
	BIT	7,(HL)		; Abnormal Termination?
	JR	Z,ERR5
	CALL	PRINT
	DEFC	'AT'
	JR	ERR13

ERR5:	BIT	4,(HL)		; Equipment Check?
	JR	Z,ERR6
	CALL	PRINT
	DEFC	'EC'
	JR	ERR13

ERR6:	BIT	3,(HL)		; Not Ready?
	JR	Z,ERR7
	CALL	PRINT
	DEFC	'NR'
	JR	ERR13

ERR7:	INC	HL		; Point to ST1
	BIT	5,(HL)		; Data Error?
	JR	Z,ERR8
	CALL	PRINT
	DEFC	'DE'
ERR8:	BIT	2,(HL)		; No Data?
	JR	Z,ERR9
	CALL	PRINT
	DEFC	' ND'
ERR9:	BIT	1,(HL)		; Write Protect?
	JR	Z,ERR10
	CALL	PRINT
	DEFC	' NW'
ERR10:	BIT	0,(HL)		; Missing Address Mark?
	JR	Z,ERR11
	CALL	PRINT
	DEFC	' MA'
ERR11:	INC	HL		; Point to ST2
	BIT	4,(HL)		; Wrong Cylinder?
	JR	Z,ERR12
	CALL	PRINT
	DEFC	' WC'
ERR12:	CALL	PRINT
	DEFC	' (T='
	LD	A,(TTRK)	; Get Track (Cyl)
	CALL	PDEC		; Print cylinder (track)
	CALL	PRINT
	DEFC	' H='
	LD	A,(HDR)
	RRCA
	RRCA
	AND	0001B
	CALL	PDEC		; Print head
	CALL	PRINT
	DEFC	' S='
	LD	A,(SECT)
	CALL	PDEC		; Print sector
	CALL	PRINT
	DEFC	')'

ERR13:	POP	DE		; Restore Regs
	POP	BC
	CALL	CONIN		; Wait for any key
	SUB	3		; ^C (reboot)?
	PUSH	AF
	CALL	PRINT
	DEFB	CR,LF+80H	; Always echo crlf
	POP	AF
	LD	A,0FFH
	RET	NZ		; ..Return Bad Status if Not user abort
	  IF  BANKED
	JP	ABORT
	  ELSE
	RST	0		; Vector thru loc 0 so wboot may be
	  ENDIF			; Intercepted by NZCOM, BGii, etc.

;.....
; Print value in A as a Decimal number (0-99)

PDEC:	LD	DE,10		; We work in decimal
PD0:	INC	D
	SUB	E
	JR	NC,PD0
	LD	E,A
	LD	A,D
	DEC	A		; Is the first digit a Zero?
	JR	Z,PD1		; ..jump if so and Don't Print
	ADD	A,'0'
	CALL	OUTCHR
PD1:	LD	A,E
	ADD	A,'0'+10
	JR	OUTCHR

;.....
; Print value in A as two Hex digits

PHEX:	PUSH	AF		; Print value in A as 2 Hex digits
	RRCA
	RRCA
	RRCA
	RRCA
	CALL	PHEX0
	POP	AF
PHEX0:	AND	0FH
	ADD	A,90H
	DAA
	ADC	A,40H
	DAA
			;..if Bioerm, fall thru to Outchr..
	  ELSE
	OR	0FFH		; Insure NZ
	RET
	  ENDIF		;Bioerm

OUTCHR:	PUSH	HL		; Print char in A to Console
	PUSH	DE
	PUSH	BC
	LD	C,A
	CALL	CONOUT
	POP	BC
	POP	DE
	POP	HL
	RET

;::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
; Point to Last Track Storage Location for the Current Drive
; Enter: None
; Exit : HL -> Last track storage for this drive
; Uses : HL

IDXTRK:	PUSH	AF		; Save regs
	LD	A,(HDR)		; Get current drive/head
	AND	0011B		;   mask off head
	LD	HL,TRKARY	; Point to track storage block
	CALL	ADDAHL		; Point to the byte
	POP	AF		;  restore regs
	RET			;   and return to caller

;:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
; Wait for FDC RQM to become Ready, and return DIO status in Zero Flag
; Pause before reading status port based on CPU Speed and Data Rate.

WRDY:	LD	A,(DLYCNT)	; Get computed delay count
WRDY0:	DEC	A		;  Done?
	JR	NZ,WRDY0	; ..loop if Not
WRDYL:	IN	A,(MSR)		; Read Main Status Register
	BIT	7,A		; Interrupt Present?
	RET	NZ		;  Return if So
	JR	WRDYL		;   Else Loop

;:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
;		D M A    S U P P O R T    R O U T I N E S
;:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
	  IF  FDDMA
; Set DMA Channel #0 for Format

STFDMA:	PUSH	AF		; Save regs
	XOR	A
	OUT0	(DSTAT),A	;  (No DMA or Interrupts)
	LD	L,D		; Get SPT value
	LD	H,0		;  extend to Word value
	LD	B,2		;   Multiply by 4 for Number of bytes
STDMA2:	ADD	HL,HL		; * 2
STDMA3:	DJNZ	STDMA2		; ..looping til done
	LD	(FDMAB+6),HL	; Save Number of bytes to transfer
	LD	HL,FDMAB	; Point to DMA Control block
	LD	BC,8*256+SAR0L	;  8 bytes from (HL)..
	OTIMR			;   to DMA Ch #0 Registers
	LD	A,01100011B	; Enable DMA on Ch #0
		; |||||||+- DME
		; ||||||+-- ?
		; ||||++--- DMA Ints (Ch1, Ch0)
		; ||++----- Bit Write En * (Ch1, Ch0)
		; ++------- DMA Enable (Ch1, Ch0)
	OUT0	(DSTAT),A	;   Command!
	POP	AF		; Restore regs
	RET

;.....
; SFDMA - Set up DMA Channel #0 for Read/Write Operation.
; Number of sectors in Reg E is multiplied by Base Sector size to obtain
; the full number of bytes to transfer.
; Enter: HL -> Read/Write Buffer
;	  A = Read/Write Command

SFDMA:	PUSH	AF		; Save Rd/Wr Command
	XOR	A
	OUT0	(DSTAT),A	; Disable DMA/DMA Ints
	   IF  BANKED
	LD	A,(SYSBNK)	; Set System Bank #
	   ELSE
	LD	A,(TPABNK)	; If Not Banked, Load TPA Bank #
	   ENDIF
	RL	H		; Place Address MSB in Carry
	ADC	A,0		;  offset Bank # by 32k banks
	RRA			;   shift Bank LSB to Carry
	RR	H		;    Move Bank # LSB (Carry) to Addr MSB
	LD	C,A		;     Save Bank #
	LD	DE,_DMA		; Get Floppy DMA IO Port Address
	LD	B,0		;  and Dummy Bank #
	POP	AF
	PUSH	AF		; Restore Rd/Wr Command
	AND	00001111B	;  keeping only low nibble
	CP	0101B		; Write?
	JR	Z,SFDMA0	; ..jump if So; CHL = Source, BDE = Dest
	EX	DE,HL		; Else
	LD	A,B		;  Swap Source
	LD	B,C		;   w/Dest
	LD	C,A
SFDMA0:	LD	(FDMAB),HL	; Save Source
	LD	A,C		;  in Block
	LD	(FDMAB+2),A
	LD	(FDMAB+3),DE	;   and Dest
	LD	A,B
	LD	(FDMAB+5),A
	LD	HL,0080H	; Set 1 Logical Sector Size for Calcs
	LD	A,(RSZ)		;  Get Physical Sector Size (in 128-byte recs)
	LD	B,A
	INC	B		;   (compensate for first DJNZ)
	JR	STDMA3		;  ..compute, set and activate
	  ENDIF		;fddma

;:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
; FDCINT - Used in the P112 as a polled routine in default configuration
;  with Interrupts disabled.  This code is assembled if the FDDMA equate
;  is set TRUE.  If your system uses Interrupts, add any additional code
;  to save Stack pointer and AF, and insure that it is in the CODE segment.
; NOTE: that the service routine MUST be in the Common Memory if Interrupts
;  (instead of polling ) are used to prevent problems when banked.
;
;:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::

;;--	CSEG		<Place the following in CSEG if "TRUE" Interrupts used>
	  IF  FDDMA
FDCINT:	     ; Set local stack if Needed, Disable Interrupts for local calls
	PUSH	BC
	PUSH	DE
	PUSH	HL
	LD	BC,0000		; Inner loop timeout
	LD	D,30		;  Outer loop timeout
	LD	HL,ST0		;   Point to Status Area
Int00:	IN0	A,(DRC)		; Read Port C
	BIT	6,A		; Int1* active?
	JR	Z,Int01		; ..jump if So
	DEC	BC		; Else count down
	LD	A,B
	OR	C
	JR	NZ,Int00	; ..loop if Not timed out
	DEC	D		;  Outer loop done?
	JR	NZ,Int00	;  ..loop if Not
	SUB	1		; Else set Carry, A=FF
	LD	(ST1),A		;  Save Bad Status
	CALL	FDRst		;   Reset the Controller
	JR	Int0X		; ..and Quit

Int01:	LD	BC,DR		; Else Point BC to Data Port
	CALL	WRDYw0
	JR	C,Int03		; ..jump if Timeout
Int02:	CALL	WRDY
	BIT	6,A		; Result phase over?
	JR	Z,Int03		; ..jump if So to Exit
	INI			; Read a byte from (C) to (HL)
	INC	B		;  (correct B for above dec)
	JR	Int02		;   and check for next

Int03:	CALL	WRDY
	LD	A,08H		; Sense Interrupt Status Comnd
	OUT	(DR),A
	CALL	WRDY
	IN	A,(DR)		; Get first Result Byte (ST0)
	CP	80H		; Invalid Command?
	JR	Z,Int0X		; ..jump to exit if So
	LD	(ST0),A		;  Else save Status Byte 0
	CALL	WRDY
	IN	A,(DR)		; Read Second Result Byte (Trk #)
	JR	Int03		; ..and loop

Int0X:	POP	HL		; Restore Regs
	POP	DE
	POP	BC
	    ; Restore Stack if Needed
	EI			; Insure Interrupts are Enabled
	RET

;.....
; Alternate entry for code that generates no "Interrupt"

FDCIN0:	PUSH	BC		; Save regs
	PUSH	DE
	PUSH	HL
	LD	HL,ST0		;  Put Status bytes here
	JR	Int01		; ..and continue mainline code
	  ENDIF		;fddma

; Wait for Interrupt maintaining watchdog timer

WRDYw0:	PUSH	BC		; Save Regs
	LD	BC,0		; Set Maximum count
WRDYw1:	IN	A,(MSR)		; Get Status
	RLA			;  Int bit to Carry
	JR	C,WRDYw2	; ..quit if Int
	DEC	BC		; Else count down
	LD	A,B
	OR	C		; Timed Out?
	JR	NZ,WRDYw1	; ..loop if Not
	CALL	FDRst		; Else Reset Controller
WRDYw2:	CCF			;  Set Carry appropriately
	POP	BC		;   restore regs
	RET

;- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

	CSEG		;*** Remainder of Code MUST be in Main Memory ***
	
;========================================================================
; Reset the Floppy Disk Controller.  Called from CBOOT in case of Hard
; Disk Boot which leaves the controller in a "hung" state, and locally
; if the Controller times out (often due to changing diskettes).

FDRst:	PUSH	AF		; Save any status
	XOR	A
	OUT	(DCR),A		; Place Controller in Reset state
	LD	A,(ACTIVE)	;  get current settings
	AND	0FCH		;   keep only motors, DMA and Ready
	OUT	(DCR),A		;  and Restore
	POP	AF		; Restore Status
	RET

;========================================================================
; Motor Off routine.  Called from TIM-DX and SELFLP2 which forces
; Motors/Timer to be Off state so spinup delay is forced on next selection.

;;ChgSpd:			; <<-- Required label for SELFLP2.  Activate
				;      label here if switching motor speed
MOTOFF:	XOR	A
	LD	(MOTIM),A	; Insure Motors Timed Out and show OFF
	LD	A,(ACTIVE)	; Get current settings
	  IF  FDDMA		;
	AND	00001111B	;  strip of Motor bits
	  ELSE
	AND	00000111B	;  strip off Motor bits and DMA
	  ENDIF
ACTIV8:	OR	00000100B	;   (insure FDC out of Reset)
	LD	(ACTIVE),A	;    save
	OUT	(DCR),A		;     and Command!
ChgSpd:	RET			; <<-- Activate label here if using 300 kb
				;      for constant 360 rpm on 5.25" Drives

;======================== RAM Storage Area ==============================

	  IF  BANKED
	COMMON	/B2RAM/		; If banked, Local stack in Bank
	  ELSE
	DSEG			; ..otherwise in Data Segment
	  ENDIF			;

	DEFS	30		; Bios R/W Entry 15-level Local Stack
FRWSTK:	DEFS	2		; Storage for Entry Stack Pointer

	DSEG			; Place in Common memory

; Add storage for DMA Control Block if using DMA Transfers
	  IF  FDDMA
FDMAB:	DEFS	2		; Source Addr (16-bits)
	DEFS	1		;  Source Bank
	DEFS	2		; Dest Addr (16-bits)
	DEFS	1		;  Dest Bank
	DEFS	2		; Byte Count of transfer
	  ENDIF		;fddma

; NOTE: Variables listed as (** Global **) are accessed by other modules and
;	MUST exist as defined.

COMND:	DEFS	1		; Storage for Command in execution
HDR:	DEFS	1		; Head (B2), Drive (B0,1)	(** Global **)
TRK:	DEFS	1		; Track (t)
HD:	DEFS	1		; Head # (h)
SECT:	DEFS	1		; Physical Sector Number
NBYTS:	DEFS	1		; Bytes/Sector (n)
EOT:	DEFS	1		; End-of-Track Sect #
GPL:	DEFS	1		; Gap Length
DTL:	DEFS	1		; Data Length

RSZ:	DEFS	1		; Bytes/Sector.  Must be placed outside of the
				;  Comnd Blk for FMTTRK to work.
; FDC Operation Result Storage Area

ST0:	DEFS	1		; Status Byte 0
ST1:	DEFS	1		; Status Byte 1 (can also be PCN)
ST2:	DEFS	1		; Status Byte 2
RC:	DEFS	1		; Track #			(** Global **)
RH:	DEFS	1		; Head # (0/1)
RR:	DEFS	1		; Sector #			(** Global **)
RN:	DEFS	1		; Sector Size			(** Global **)

ACTDMA:	DEFS	2		; 16-bit DMA Address

;-->>>  Do NOT re-order the following two bytes !! <<<--

MTM:	DEFS	1		; Floppy Time down-counter
MOTIM:	DEFS	1		; Motor On Time Counter

; DISK Subsystem Variable Storage

FDMOT:	DEFS	1		; Motor on required flag
RDOP:	DEFS	1		; Read/write flag
RETRYS:	DEFS	1		; Number of times to try Opns
RWRTRY:	DEFS	1		; Number of read/write tries
DRVSPD:	DEFS	1		; Drive Speed
DRVSIZ:	DEFS	1		; Drive Size
STEP2:	DEFS	1		; <> 0 for Double Step		(** Global **)
MODE:	DEFS	1		; Bit 6 = 1 if MFM, 0 = FM
ACTIVE:	DEFS	1		; Current bits written to Dev Contr Reg (DCR)
DLYCNT:	DEFS	1		; Delay value reading Main Status Reg
FSPT:	DEFS	1		; Format Sectors/Track value
TSBSCF:	DEFS	1		; 0=Hd always 0 (TSBSC)		(** Global **)

TTRK:	DEFS	1		; Storage for Track		(** Global **)
TRKARY:	DEFS	4		; Track storage locations for four drives

;=========================== End of FDC-DX ==============================