;*****************************************************************************
;*									     *
;*	PROGRAM TO CONTROL THE TRACK POSITION, ETC. OF 5 1/4 INCH	     *
;*	FLOPPY DRIVES TO MAKE HEAD ALIGNMENT POSSIBLE.			     *
;*			BY RONALD E. JACOBS				     *
;*			 NOVEMBER 1, 1983				     *
;*									     *
;*	05/22/86 added microdecision drive control capabilities		     *
;*****************************************************************************


	.Z80			;written in Z80 assembly language
	ORG 0			;for use with M80/L80

;************************************************************************
;*									*
;*	the following is a user setable equate				*
;*									*
;************************************************************************

	diradfg	equ	1	;0 for freedom; 1 for adm 31 cursor addressing


	CR	EQU	0Dh	;CARRIAGE RETURN
	LF	EQU	0Ah	;LINE FEED
	BDOS	EQU	5

	LD	SP,STACK	;STARTING ADDR OF STACK

	CALL	RDTAIL		;SEE IF FOR 8" OR 5" DRIVES AND PATCH IF NEEDED
	CALL	DISPLA		;WRITE THE CRT SCREEN DISPLAY

COMAND:	LD	B,44		;COLUMN ADDRESS (NO OFFSET)
	LD	C,19		;ROW ADDRESS (NO OFFSET)
	CALL	CURADD		;MOVE CURSOR TO 'Command:'
	CALL 	GETCHR

;****************************************************************
;*								*
;*	SEE IF CHARACTER JUST RECEIVED FROM CONSOLE WAS		*
;*	A DIGIT (0-3).  IF SO, CHECK FOR A SECOND DIGIT.	*
;*	IF NOT CHECK TO SEE IF CHARACTER IS A VALID LETTER.	*
;*								*
;****************************************************************

	LD 	B,4		;COUNT
TRHCNT	EQU	$-1		;TRACK HIGH DIGIT COUNT
	LD 	C,'3'		;3 FOR 5" OR 7 FOR 8" DRIVES
TRHDIG	EQU	$-1		;HIGHEST TRACK DIGIT
DIGIT:	CP	C
	JP	Z,TRACK		;IF A DIGIT, GET 2nd DIGIT
	DEC	C		;NEXT LOWER ASCII DIGIT
	DJNZ	DIGIT		;ALL 4 DIGITS TRIED YET ?
	JR	ALPHA		;NOT A DIGIT, GO SEE IF ALPHA COMMAND


;*****************************************************************
;*								*
;*	DETERMINE IF A VALID LETTER COMMAND WAS TYPED 		*
;*	AND TAKE APPROPRIATE ACTION				*
;*								*
;*****************************************************************


ALPHA:	CP	'C'
	JP	Z,CURREV
	CP	'c'
	JP	Z,CURREV

	CP	'I'
	JP	Z,STEPI
	CP	'i'
	JP	Z,STEPI

	CP	'O'
	JP	Z,STEPO
	CP	'o'
	JP	Z,STEPO

	CP	'R'
	JP	Z,RECAL
	CP	'r'
	JP	Z,RECAL

	CP	'S'
	JP	Z,SIDSEL
	CP	's'
	JP	Z,SIDSEL

MOTCHR:	CP	'M'
	JP	Z,MOTOR
	CP	'm'
	JP	Z,MOTOR

	CP	'L'
	JP	Z,SELDRV
	CP	'l'
	JP	Z,SELDRV

	CP	03h		;03h= ^C
	JP	Z,EXIT		;WARM BOOT

	JP	COMAND		;CHAR TYPED WASN'T VALID COMMAND

;****************************************************************
;*								*
;*			CURREV ROUTINE				*
;*								*
;*	TOGGLES A FLAG (RCXCHG) WHICH THE CURSOR ADDRESSING	*
;*	ROUTINE USES TO REVERSE OR NOT REVERSE THE ORDER	*
;*	OF TRANSMISSION OF ROW AND COLUMN TO THE TERMINAL.	*
;*								*
;****************************************************************

CURREV:	LD	A,(RCXCHG)
	OR	A
	JP	Z,REV

	LD	A,0
	LD	(RCXCHG),A
	JP	COMAND

REV:	LD	A,1
	LD	(RCXCHG),A
	JP	COMAND


;****************************************************************
;*								*
;*			EXIT ROUTINE				*	
;*								*
;*	1. RESTORE ORIGINAL DEFAULT DRIVE			*
;*	2. RESTORE ORIGINAL 8",5-1/4" DRIVE ORDER		*
;*	3. MOVE CURSOR TO SCREEN BOTTOM LEFT			*
;*	4. WARM BOOT						*
;*								*
;****************************************************************

EXIT:	ld	a,(mdflag)	;0=djdma, 1=microdecision
	or	a		;test if djdma or microdecision
	jp	nz,wboot	;skip decision 1 housekeeping

	LD	C,0Eh		;BDOS SELECT DISC
	LD	A,(ORGDSK)	;RESTORE ORIGINAL DEFAULT DRIVE
	LD	E,A
	CALL	BDOS

	LD	A,(PHYDRV)	;WAS ORIGINAL DRIVE 0 8 OR 5 INCH
	AND	00000100b	;IN BIT 2=0 THEN ORIGINALLY 8"
	LD	(ORDR58),A	;PATCH INTO SUBROUTINE MFFRST
	CALL	MFFRST		;RESTORE ORIGINAL 8, 5" DRIVE ORDER

	LD	A,16d		;RESTORE DJDMA DRIVE DESELECT TIME 
	LD	(DESTIM),A	;STORE BYTE IN DJDMA COMMAND STRING
	CALL	DESEL

	LD	A,10d		;RESTORE DJDMA ERROR RETRYS COUNT
	LD	(RETNUM),A	;STORE BYTE IN DJDMA COMMAND STRING
	CALL	RETRYS

wboot:	LD	B,0		;COLUMN ADDRESS (NO OFFSET)
	LD	C,23		;ROW ADDRESS (NO OFFSET)
	CALL	CURADD		;POSITION THE CURSOR FOR EXIT
	JP	0		;WARM BOOT

;****************************************************************
;*								*
;*			MOTOR ROUTINE				*
;*								*
;****************************************************************

MOTOR:	LD	B,2Ah			;COLUMN ADDR (NO OFFSET)
	LD	C,13			;ROW ADDR (NO OFFSET)
	CALL	CURADD			;CURSOR ADDR SUBROUTINE

	LD	A,(MOTOGL)		;MOTOR TOGGLE FLAG
	CP	0
	JP	Z,MOTRON
	LD	C,09h			;BDOS PRINT STRING FUNCTION
	LD	DE,OFFMSG		;START OF OFF MESSAGE STRING
	CALL	BDOS
	XOR	A
	LD	(MOTOGL),A
	JP	COMAND			;RETURN FOR NEXT COMMAND

MOTRON:	LD	C,09h			;BDOS PRINT STRING FUNCTION
	LD	DE,ONMSG		;START OF ON MESSAGE STRING
	CALL	BDOS
	LD	A,1
	LD	(MOTOGL),A
	JP	COMAND			;RETURN FOR NEXT COMMAND

MOTOGL:	DB	0			;MOTOR TOGGLE FLAG
OFFMSG:	DB	'OFF     $'		;EXTRA WHITE SPACE FOR PATCH USE
ONMSG:	DB	'ON      $'		; WITH 8"DRIVES


;****************************************************************
;*								*
;*			RECAL ROUTINE				*
;*								*
;*	1. WRITES CONTROLLER COMMANDS TO 50h			*
;*	2. CAUSES CONTROLER TO EXECUTE THESE COMMANDS		*
;*	3. CONTROLLER COPIES BYTES FROM MAIN MEMORY TO 		*
;*	   CONTROLLER MEMORY (1030h).				*
;*	4. CONTROLLER BEGINS EXECUTING INSTRUCTIONS AT 1030h	*
;*	5. THE INSTRUCTIONS AT 1030h CALL THE CONTROLLERS	*
;*	   HOME HEAD ROUTINE					*
;*	6. AT COMPLETION OF THIS CONTROLLER EXECUTES THE HALT	*
;*	   COMMAND. DURING THE ABOVE STEPS THE MAIN CPU IS	*
;*	   WAITING FOR THE HALT COMMAND (25h) STATUS BYTE TO 	*
;*	   CHANGE FROM 00 TO INDICATE THE DJDMA IS FINISHED	*
;*								*
;****************************************************************


;* THESE BYTES WILL BE LOADED INTO CONTROLLERS MEMORY AT 1030h *

HOMEHD:	DB	0CDh		;CALL INSTRUCTION
	DW	00A0h		;ADDRESS ON DJDMA OF JUMP VECTOR TO HOME ROUTINE
HOMEND:	DB	0C9h		;RETURN INSTRUCTION


;* THESE BYTES WILL BE LOADED INTO MAIN MEMORY AT 0050h *

WRTCOM:	DB	0A1h		;DJDMA WRITE CONTROLLER MEMORY COMMAND
	DW	HOMEHD		;STARTING ADDRESS OF STRING TO TRANSFER
	DB	00		;EXTENDED ADDRESS OF STRING TO TRANSFER
	DW	HOMEND-HOMEHD+1	;NUMBER OF BYTES IN STRING BEING TRANSFERED
	DW	1030h		;TRANSFER STRING TO 1030h IN CONTROLLER MEMORY
	DB	0A2h		;DJDMA EXECUTE CONTROLLER ROUTINE COMMAND
	DW	1030h		;ADDRESS IN CONTROLLER TO BEGIN EXECUTING AT
	DB	25h		;DJDMA CONTROLLER HALT COMMAND
WRTHLT:	DB	00		;HALT COMMAND STATUS BYTE
	
RECAL:	LD	HL,WRTCOM	;ADDRESS TO BEGIN TRANSFERRING BYTES FROM
	LD	BC,WRTHLT-WRTCOM+1	;NUMBER OF BYTES TO TRANSFER
	LD	DE,0050h	;ADDRESS TO BEGIN TRANSFERRING BYTES TO
	LDIR			;DOES THE TRANSFER
	OUT	(0EFh),A	;START THE DJDMA

WRTDON:	LD	A,(WRTHLT-WRTCOM+50h) ;ACTUAL HALT STATUS BYTE ADDRESS
	OR	A		;HAS HALT COMMAND COMPLETED ?
	JP	Z,WRTDON

	CALL 	RUNONE		;RUN READ SECTOR ONCE 
	JP 	COMAND		;RETURN FOR NEXT COMMAND


;****************************************************************
;*								*
;*			SELDRV ROUTINE				*
;*								*
;****************************************************************

SELDRV:	LD	B,2Ah		;COLUMN ADDRESS (NO OFFSET)
	LD	C,15		;ROW ADDRESS (NO OFFSET)
	CALL	CURADD		;MOVE CURSOR TO DRIVE LETTER POSITION
DRVCHR:	CALL	GETCHR		;GET ACTUAL DRIVE NUMBER FROM TERMINAL
	CP	'0'		;VALID CHARACTER IS 0-3
	JP	Z,SELPNT
	CP	'1'
	JP	Z,SELPNT
	CP	'2'
	JP	Z,SELPNT
	CP	'3'
	JP	Z,SELPNT
	JP	DRVCHR		;CHARACTER WASN'T VALID; TRY AGAIN

SELPNT:	LD	C,6		;BDOS DIRECT CONSOLE I/0
	LD	E,A		;PRINT SELECTED DRIVE ON CRT
	AND	00001111b	;CONVERT ASCII DIGIT TO BINARY
	LD	(MOTDRV),A	;STORE DRIVE NUMBER	
	CALL	BDOS

	JP	COMAND		;RETURN FOR NEXT COMMAND

	
;****************************************************************
;*								*
;*			SIDSEL ROUTINE				*
;*								*
;*	TOGGLE THE CHOSEN SIDE, DISPLAY CHOICE ON CRT,		*
;*	STORE CHOICE FOR USE BY MOTRUN SUBROUTINE		*
;*								*
;****************************************************************

SIDSEL:	LD	B,29h		;COLUMN ADDRESS (NO OFFSET)
	LD	C,11		;ROW ADDRESS (NO OFFSET)
	CALL	CURADD		;CURSOR ADDRESS SUBROUTINE

	LD	A,(MOTSS)	;MOTOR SIDE/SECTOR BYTE
	BIT	7,A		;BIT 7 SELECTS SIDE
	JP	Z,SIDE1

	RES	7,A		;SELECT SIDE 0
	LD	(MOTSS),A	;STORE BYTE IN DJDMA COMMAND STRING
	LD	C,06h		;BDOS DIRECT CONSOLE I/O
	LD	E,'0'		;PRINT SIDE ON CRT
	CALL	BDOS
	ld	a,0		;bit 2 selects microdecision head
	ld	(mdside),a	;store byte in microdecision seek command
	JP	COMAND

SIDE1:	SET	7,A		;SELECT SIDE 1
	LD	(MOTSS),A	;STORE BYTE IN DJDMA COMMAND STRING
	LD	C,06h		;BDOS DIRECT CONSOLE I/O
	LD 	E,'1'		;PRINT SIDE ON CRT
	CALL	BDOS
	ld	a,00000100b	;bit 2 selects microdecision head
	ld	(mdside),a	;store byte in microdecision seek command
	JP	COMAND


;****************************************************************
;*								*
;*			STEPI ROUTINE				*
;*								*
;*	INCREMENT THE ASCII REPRESNTATION OF THE CURRENT TRACK  *
;*	NUMBER BY ONE (IF NOT ALREADY HIGHEST TRACK). PRINT IT	*
;*	ON THE CRT AND INSERT IT IN THE DJDMA READ SECTOR 	*
;*	COMMAND STRING.						*
;*								*
;****************************************************************

STEPI:	LD 	A,(MOTTRK)	;CURRENT TRACK IN HEX
HITRAK:	CP	39d		;HIGHEST ALLOWED TRACK NUMBER
	JP	Z,COMAND	;DON'T STEP IN IF ALREADY AT 39

	LD	A,(DIGIT2)	;ASCII ONES DIGIT OF CURRENT TRACK
	CP	'9'		;IS IT AN ASCII 9 ?
	JP	NZ,TRKINC	;IF LESS THEN 9 INCREMENT IT 1

;*IF ONES DIGIT IS A 9:*
	LD	A,30h		;ASCII 0
	LD	(DIGIT2),A	;STORE A 0 IN ONES DIGIT OF TRACK
	LD	A,(DIGIT1)	;OLD ASCII TENS DIGIT OF TRACK #
	INC	A		;INCREMENT TENS BY 1
	LD	(DIGIT1),A	;STORE IT
	CALL	TRKCRT		;PRINT THE NEW TRACK NUMBER ON CRT
	CALL	TRKHEX		;CONVERT TO HEX TRACK #, PUT IN COMMAND
	JP	COMAND		;GO GET NEXT COMMAND FROM TERMINAL

;*IF ONES DIGIT IS 0 TO 8 :*
TRKINC:	INC	A		;INCREMENT ONES DIGIT BY ONE
	LD	(DIGIT2),A	;STORE IT
	CALL	TRKCRT		;PRINT THE NEW TRACK # ON CRT
	CALL	TRKHEX		;CONVERT TO HEX TRACK #, PUT IN COMMAND
	JP	COMAND		;GO GET NEXT COMMAND FROM TERMINAL


;****************************************************************
;*								*
;*			STEPO ROUTINE				*
;*								*
;*	DECREMENT THE ASCII REPRESNTATION OF THE CURRENT TRACK  *
;*	NUMBER BY ONE (IF NOT ALREADY LOWEST TRACK). PRINT IT	*
;*	ON THE CRT AND INSERT IT IN THE DJDMA READ SECTOR 	*
;*	COMMAND STRING.						*
;*								*
;****************************************************************

STEPO:	LD 	A,(MOTTRK)	;CURRENT TRACK IN HEX
	CP	00d		;LOWEST ALLOWED TRACK NUMBER
	JP	Z,COMAND	;DON'T STEP OUT IF ALREADY AT 00

	LD	A,(DIGIT2)	;ASCII ONES DIGIT OF CURRENT TRACK
	CP	30h		;IS IT AN ASCII 0 ?
	JP	NZ,TRKDEC	;IF GREATER THEN 0 DECREMENT IT 1

;*IF ONES DIGIT IS A 0:*
	LD	A,39h		;ASCII 9
	LD	(DIGIT2),A	;STORE A 9 IN ONES DIGIT OF TRACK
	LD	A,(DIGIT1)	;OLD ASCII TENS DIGIT OF TRACK #
	DEC	A		;DECREMENT TENS BY 1
	LD	(DIGIT1),A	;STORE IT
	CALL	TRKCRT		;PRINT THE NEW TRACK NUMBER ON CRT 
	CALL	TRKHEX		;CONVERT TO HEX TRACK #, PUT IN COMMAND
	JP	COMAND		;GO GET NEXT COMMAND FROM TERMINAL

;*IF ONES DIGIT IS 1 TO 9:*
TRKDEC:	DEC	A		;DECREMENT ONES DIGIT BY ONE
	LD	(DIGIT2),A	;STORE IT
	CALL	TRKCRT		;PRINT THE NEW TRACK NUMBER ON CRT
	CALL	TRKHEX		;CONVERT TO HEX TRACK #, PUT IN COMMAND
	JP	COMAND		;GO GET NEXT COMMAND FROM TERMINAL

;****************************************************************
;*								*
;*			TRACK ROUTINE				*
;*								*
;*	TAKE THE ASCII TRACK NUMBER FROM THE 			*
;*	DE REGISTER PAIR AND SEND THE HEAD TO THAT TRACK	*
;*	AND DISPLAY IT ON THE SCREEN.				*
;*								*
;****************************************************************

TRACK:	LD	(DIGIT1),A	;SAVE THE FIRST DIGIT

	LD	B,2Ah		;COLUMN ADDRESS (NO OFFSET)
	LD	C,09d		;ROW ADDRESS (NO OFFSET)
	CALL	CURADD		;MOVE CURSOR TO TRACK NUMBER POSITION

	LD	C,6		;BDOS DIRECT CONSOLE I/O
	LD	A,(DIGIT1)
	LD	E,A		;PRINT THE FIRST DIGIT
	CALL	BDOS

GET2ND:	CALL	GETCHR		;GET THE 2nd DIGIT OF TRACK NUMBER
	LD	(DIGIT2),A	;SAVE THE SECOND CHARACTER

;*identify what digit the second character is, if any:*

	LD	B,0Ah		;COUNT
	LD	C,39h		;ASCII 9
LOOP:	CP	C
	JP	Z,LMIT76	;IF DIGIT IDENTIFIED
	DEC	C		;TRY NEXT LOWER DIGIT
	DJNZ	LOOP		;ALL 10 DIGITS TRIED YET ?
	JP	GET2ND		;ERROR: CHARACTER NOT 0-9

;*don't allow tracks higher than 76 *

LMIT76:	LD	A,(DIGIT1)	;TENS DIGIT OF TRACK NUMBER
	CP	'7'
	JP	NZ,TRKPNT	;OK IF TENS DIGIT LESS THAN 7
	LD	A,(DIGIT2)	;TENS MUST=7 SO CHECK 2nd DIGIT
	CP	'7'
	JP	NC,GET2ND	;BAD IF ONES GREATER THAN 6

TRKPNT:	LD	C,6		;BDOS DIRECT CONSOLE I/O
	LD	A,(DIGIT2)	;PRINT THE SECOND DIGIT
	LD	E,A
	CALL	BDOS

	CALL	TRKHEX		;CONVERT ASCII TRACK TO HEX,LOAD IN

	JP	COMAND		;GO GET NEXT COMMAND FROM CONSOLE

DIGIT1:	DB	31h		;ASCII 1  \ MAKES ASCII TRACK 
DIGIT2:	DB	36h		;ASCII 6  / NUMBER 16



;****************************************************************
;*								*
;*			CURADD SUBROUTINE			*
;*								*
;*	DIRECT CURSOR ADDRESSING SUBROUTINE: upon entry		*
;*	to CURADD reg. B should contain COLUMN addr without	*
;*	offset.  Reg. C should contain ROW address without	*
;*	offset.							*
;*								*
;****************************************************************

CURADD:	LD	A,20h			;COLUMN OFFSET
	ADD	A,B
	LD	(COL),A			;STORE COLUMN (ADDR+OFFSET)

	LD	A,20h			;ROW OFFSET
	ADD	A,C
	LD	(ROW),A			;STORE ROW (ADDRESS+OFFSET)

	LD	C,6			;BDOS DIRECT CONSOLE I/O
	LD	E,1Bh			;esc character-TERMINAL DEPENDENT
	CALL	BDOS

	LD	C,6			;BDOS DIRECT CONSOLE I/O
	LD	E,'='			;= character-TERMINAL DEPENDENT
	CALL	BDOS			;OUTPUT CHARACTER

	LD	A,(RCXCHG)		;IS ORDER OF TRANSMISSION OF
	OR	A			;ROW AND COLUMN TO BE REVERSED ?
	JP	NZ,COLOUT

ROWOUT:	LD	C,6			;BDOS DIRECT CONSOLE I/O
	LD	A,(COL)			;OUTPUT COLUMN ADDRESS
	LD	E,A
	CALL	BDOS

	LD	A,(RCXCHG)		;IS COLUMN NEXT OR ARE WE DONE ?
	OR	A
	JP	NZ,CURRET

COLOUT:	LD	C,6			;BDOS DIRECT CONSOLE I/O
	LD	A,(ROW)			;OUTPUT ROW ADDRESS
	LD	E,A
	CALL	BDOS

	LD	A,(RCXCHG)		;ARE WE DONE OR IS ROW NEXT ?
	OR	A
	JP	NZ,ROWOUT

CURRET:	RET

ROW:	DS	1
COL:	DS	1
RCXCHG:	DB	diradfg			;use 0 for freedom, use 1 for adm 31


;****************************************************************
;*								*
;*			DESEL SUBROUTINE			*
;*								*
;*	SETS THE NUMBER OF REVOLUTIONS BEFORE THE DJDMA		*
;*	IS DESELECTED AFTER DISC ACTIVITY.			*
;*								*
;**************************************************************** 

DESCOM:	DB	2Fh	;HEAD UNLOAD DRIVE DESELECT TIMEOUT COMMAND
DESTIM:	DB	03h		;NUMBER OF REVOLUTIONS BEFORE TIMEOUT
	DB	25h		;DJDMA HALT COMMAND
DESHLT:	DB	00h		;STATUS BYTE

DESEL:	LD	HL,DESCOM	;ADDRESS TO BEGIN TRANSFERING BYTES FROM
	LD	DE,0050h	;ADDRESS TO BEGIN TRANSFERING BYTES TO
	LD	BC,04		;NUMBER OF BYTES TO TRANSFER
	LDIR			;DOES THE TRANSFER
	OUT 	(0EFh),A	;START THE DJDMA

DESDON:	LD	A,(DESHLT-DESCOM+50h);ACTUAL HALT STATUS BYTE ADDRESS
	OR	A		;HAS HALT COMMAND COMPLETED ?
	JP	Z,DESDON

	RET


;****************************************************************
;*								*
;*			DISPLA SUBROUTINE			*
;*								*
;*	SUBROUTINE: SCROLLS WHATEVER IS ON THE SCREEN OFF	*
;*	AND DISPLAYS THE MFSTEP COMMANDS AND OTHER INFORMATION	*
;*	ON THE SCREEN.						*
;*								*
;****************************************************************


DISPLA:	LD 	C,09h		;BDOS PRINT STRING FUNCTION
	LD	DE,SCREEN	;START ADDR OF STRING
	CALL	BDOS		;BDOS ENTRY POINT
	RET

SCREEN:	DB	LF,LF,LF,LF,LF,LF,LF,LF
	DB	LF,LF,LF,LF,LF,LF,LF,LF,LF,LF
	DB	LF,LF,LF,LF,LF,LF
DRVSIZ:	DB	'DJDMA 5 1/4" FLOPPY DRIVE ALIGNMENT TOOL '
	DB	CR,LF
	DB	'REVISION 2.0  MAY 22, 1986 Jacobs Computer Services'
	DB	LF,LF,LF,LF,LF,CR
	DB	'step (I)n 1 track   '
	DB	CR,LF,LF	
	DB	'step (O)ut 1 track  '
	DB	CR,LF
	DB	'                                    TRACK 16'
	DB	CR,LF,'seek to track (NN)  '
	DB	CR,LF
	DB	'                                    SIDE 0'
	DB	CR,LF,'(R)ecalibrate       '
	DB	CR,LF
MOT5:	DB	'                                    MOTOR OFF    '
	DB	CR,LF,'(M)otor on/off         '
	DB	CR,LF
	DB	'                                    DRIVE 0'
	DB	CR,LF
	DB	'(S)ide 0-1'
	DB	CR,LF,LF
	DB	'drive se(L)ect (0-3)'
	DB	CR,LF
	DB	'                                    Command:'
	DB	CR,LF
	DB	'^C = EXIT'
	DB	CR,LF,LF
	DB	'(C)ursor addressing'
	DB	LF,'$'


	DS	100h		;STACK SPACE
STACK	EQU	$



;****************************************************************
;*								*
;*		SUBROUTINE DRVORD				*
;*								*
;*	 SAVE THE ORIGINAL DEFAULT DISC				*
;*								*
;****************************************************************

DRVORD:	LD	C,19h		;BDOS RETURN CURRENT DISC
	CALL	BDOS
	LD 	(ORGDSK),A	;SAVE CURRENT DEFAULT DISC

	RET

ORGDSK:	DS	1


;****************************************************************
;*								*
;*			GETCHR SUBROUTINE			*
;*								*
;*	FETCHES A CHARACTER FROM THE CONSOLE.			*
;*	RETURNS IT IN REGISTER A. AND SINCE THIS ROUTINE IS	*
;*	NEARLY ALWAYS RUNNING, IT KEEPS THE MOTOR RUNNING BY	*
;*	CALLING MOTRUN.						*
;*								*
;****************************************************************

GETCHR:	LD	C,06		;BDOS DIRECT CONSOLE I/O
	LD 	E,0FFh		;FOR CONSOLE INPUT
	CALL	BDOS
	PUSH	AF
	CALL	MOTRUN
	POP	AF
	CP	0		;IF 0 THEN NO CHARACTER WAS READY
	JR	Z,GETCHR	;TRY AGAIN TO GET A CHARACTER
	RET


;********************************************************
;*							*
;*			SUBROUTINE MFFRST		*
;*							*
;*	1. SETS 5-1/4" DRIVES TO 0-3 (OR 4-8 IF ORDR58	*
;*	   =0) AND 8" TO 4-8 (OR 0-4 IF ORDR58=0)	*
;*	2. SAVE THE ORIGINAL DRIVE ORDER		*
;*							*
;********************************************************

SETDRV:	DB	2Eh		;DJDMA SET LOGICAL DRIVE COMMAND
ORDR58:	DB	4		;SET ORDER OF 8" AND 5-1/4" DRVS
PHYDRV:	DB	0		;STATUS BYTE
	DB	25H		;DJDMA HALT CONTROLLER COMMAND
PHYHLT:	DB	00		;STATUS BYTE

MFFRST:	LD	HL,SETDRV	;START ADDR OF BLOCK TO TRANSFER BYTES FROM
	LD	DE,0050h	;START ADDRESS OF BLOCK TO TRANSFER BYTES TO
	LD	BC,5		;NUMBER OF BYTES TO TRANSFER
	LDIR			;DOES THE TRANSFER
	OUT	(0EFh),A	;KICK DJDMA

PHYDON:	LD	A,(PHYHLT-SETDRV+50h)	;HAS DJDMA HALT INSTRUCTION COMPLETED ?
	OR	A
	JP	Z,PHYDON		;TRY AGAIN IF NOT

	RET

;****************************************************************
;*								*
;*			SUBROUTINE MOTRUN			*
;*								*
;*	KEEP MOTOR RUNNING IF MOTOR ON (MOTOGL=1) SELECTED	*
;*	DO THIS BY GIVING THE READ SECTOR COMMAND		*
;*								*
;****************************************************************

MOTRUN:	LD	A,(MOTOGL)	;0=MOTOR OFF  1=ON
	CP	0
	RET	Z		;RETURN IF DESIRED OFF
	CALL	RUNONE		;GIVE A READ SECTOR COMMAND (MAKES MOTOR RUN)
	RET


;****************************************************************
;*								*
;*			SUBROUTINE RDTAIL			*
;*								*
;*	READS THE COMMAND TAIL (e.g. A> FSTEP 8 ), DETERMINES	*
;*	IF FOR 5 1/4 OR FOR 8" DRIVES.  IF FOR  8" PATCHES	*
;*	THE PROGRAM ACCORDINGLY. IF FOR 5" DOES NOT PATCH AS	*
;*	PROGRAM IS ALREADY SET UP FOR 5 1/4" DRIVES.		*
;*								*
;*	IF FOR MICRODECION, PATCHES THE PROGRAM ACCORDINGLY	*
;*								*
;****************************************************************


RDTAIL:	LD	A,(80h)		;FIND NUMBER OF BYTES IN COMMAND TAIL
	CP	2		;OK IF 2 BYTES (A SPACE AND HOPEFULLY A DIGIT)
	JP	NZ,ERRMSG	;NOT OK IF NOT 2 BYTES, GIVE ERROR MESSAGE 
	LD	A,(82h)		;LOAD THE ASCII CHARACTER FROM THE TAIL

	cp	'm'		;see if tail character is an 'm'
	jp	z,mdpatch	;patch to work with microdecision drives
	cp	'M'		;see if tail character is an 'M'
	jp	z,mdpatch	;patch to work with microdecision drives
	CP	'5'		;SEE IF TAIL CHARACTER IS A '5'
	JP	Z,D1INIT	;DON'T PATCH SCREEN, DO DECISION 1 INITIALIZE;RET	Z		;NO PATCHING NEEDED, BEGIN PROGRAM
	CP	'8'		;WASN'T A '5', IS IT AN '8'?
	JP	NZ,ERRMSG	;NOT A '5' OR '8' SO GIVE ERROR MESSAGE

;* PATCH FSTEP TO WORK WITH 8" INSTEAD OF 5" DRIVES *

patch8:	LD	A,0
	LD	(ORDR58),A	;SET ORDER TO 8" FOLLOWED BY 5" DRIVES

	LD	DE,MOT5		;START ADDRESS TO TRANSFER BLOCK TO
	LD	HL,MOT8		;START ADDRESS TO TRANSFER BLOCK FROM
	LD	BC,MOT8ND-MOT8	;NUMBER OF BYTES TO TRANSFER
	LDIR			;DOES THE TRANSFER

	LD	DE,DRVSIZ	;START ADDRESS TO TRANSFER BLOCK TO
	LD	HL,SIGNON	;START ADDRESS TO TRANSFER BLOCK FROM
	LD	BC,SIGNND-SIGNON	;NUMBER OF BYTES TO TRANSFER
	LDIR			;DOES THE TRANSFER

	LD	DE,OFFMSG	;START ADDRESS TO TRANSFER BLOCK TO
	LD	HL,OFFMS8	;START ADDRESS TO TRANSFER BLOCK FROM
	LD	BC,OFFND8-OFFMS8  ;NUMBER OF BYTES TO TRANSFER
	LDIR			;DOES THE TRANSFER

	LD	DE,ONMSG	;START ADDRESS TO TRANSFER BLOCK TO
	LD	HL,ONMS8	;START ADDRESS TO TRANSFER BLOCK FROM
	LD	BC,ONND8-ONMS8	;NUMBER OF BYTES TO TRANSFER
	LDIR			;DOES THE TRANSFER

	LD	A,8		;FOR CHANGE TO 8 POSSIBLE DIGITS
	LD	(TRHCNT),A	;NUMBER OF POSSIBLE TENS DIGITS IN TRACK NUMBER

	LD	A,'7'		;FOR CHANGE TO MAX 77 TRACKS
	LD	(TRHDIG),A	;HIGHEST POSSIBLE ASCII TENS DIGIT IN TRACK

	LD	A,41d		;FOR CHANGE TO HEAD LOAD/UNLOAD
	LD	(MOTOR+1),A	;MOTOR ON-OFF COLUMN ADDRESS

	LD	A,'H'		;PATCH MOTOR ON/OFF CHARACTER FOR 
	LD 	(MOTCHR+1),A	;HEAD LOAD/UNLOAD
	LD	A,'h'
	LD	(MOTCHR+6),A

	LD	A,76d		;FOR CHANGE TO 76 TRACKS
	LD	(HITRAK+1),A	;HIGHEST TRACK NUMBER


D1INIT:	CALL	DESEL		;SET DJDMA TO FASTEST DRIVE DESELECT TIME
	CALL	RETRYS		;SET DJDMA TO LOWEST NUMBER OF RETRYS
	CALL	MFFRST		;ORDER 5 1/4" BEFORE 8" DRIVES
	CALL	DRVORD		;SAVE THE ORIGINAL DEFAULT DISC
	RET			;PATCHING COMPLETED

ERRMSG:	LD	C,9		;BDOS PRINT STRING FUNCTION
	LD	DE,USEAGE	;STRING TO PRINT
	CALL	BDOS

	JP 	0		;WARM BOOT

USEAGE:	DB	CR,LF
	DB	'usage:'
	DB	CR,LF,LF
	DB	'FSTEP 5   for 5 1/4" drives controlled by DJDMA'
	DB	CR,LF
	DB	'FSTEP 8   for 8" drives controlled by DJDMA'
	db	cr,lf
	db	'FSTEP M   for 5 1/4" drives controlled by MicroDecision'
	DB	CR,LF,'$'

SIGNON:	DB	'DJDMA 8" FLOPPY DRIVE ALIGNMENT TOOL     '
SIGNND	EQU	$

OFFMS8:	DB	'UNLOADED$'
OFFND8	EQU	$

ONMS8:	DB	'LOADED  $'
ONND8	EQU	$

MOT8:	DB	'                                    HEAD UNLOADED'
	DB	CR,LF,'(H)ead loaded/unloaded'
MOT8ND	EQU	$


;*************************************************************************
;*									 *
;*	PATCH THE SCREEN DISPLAY FOR USE WITH MICRODECISION CONTROLLED   *
;*	DRIVES								 *
;*									 *
;*************************************************************************

mdpatch:ld	a,1		;1=microdecision controlled drive
	ld	(mdflag),a	;store flag indicating microdec. for later use

	LD	DE,DRVSIZ	;START ADDRESS TO TRANSFER BLOCK TO
	LD	HL,mdSIGN	;START ADDRESS TO TRANSFER BLOCK FROM
	LD	BC,mdSIGND-mdSIGN	;NUMBER OF BYTES TO TRANSFER
	LDIR			;DOES THE TRANSFER

	RET			;PATCHING COMPLETED

mdflag:	db	0		;0=djdma; 1=microdecision controlled drive 

mdSIGN:	DB	'MICRODECISION FLOPPY DRIVE ALIGNMENT TOOL'
mdSIGND	EQU	$


;****************************************************************
;*								*
;*			SUBROUTINE RETRYS			*
;*								*
;*	SETS THE NUMBER OF RETRYS THE DJDMA MAKES WHEN A CRC	*
;*	ERROR OCCURS IN THE DATA FIELD.				*
;*								*
;****************************************************************

RETCOM:	DB	28h		;SET ERROR RETRY COUNT COMMAND
RETNUM:	DB	01		;INITIALIZE TO LOWEST NUMBER
	DB	25h		;DJDMA HALT CONTROLLER COMMAND
RETHLT:	DB	00		;STATUS BYTE

RETRYS:	LD	HL,RETCOM	;START ADDRESS OF BLOCK TO TRANSFER FROM
	LD	DE,0050h	;START ADDR OF BLOCK TO TRANSFER TO
	LD	BC,04		;NUMBER OF BYTES TO TRANSFER
	LDIR			;DOES THE TRANSFER
	OUT 	(0EFh),A	;START THE DJDMA

RETDON:	LD	A,(RETHLT-RETCOM+50h);ACTUAL HALT STATUS BYTE ADDRESS
	OR	A		;HAS HALT COMMAND COMPLETED ?
	JP	Z,RETDON

	RET	


;****************************************************************
;*								*
;*			SUBROUTINE RUNONE			*
;*								*
;*	GIVE ONE READ SECTOR COMMAND.  THIS MAKES THE MOTOR	*
;*	RUN  FOR  5 1/4" DRIVES (OR THE HEAD LOAD FOR 8" 	*
;*	DRIVES) 						*
;*								*
;****************************************************************


MOTCMD:	DB	20h		;DJDMA READ SECTOR COMMAND
MOTTRK:	DB	16		;TRACK #(FILLED BY ROUTINE TRACK)
MOTSS:	DB	00000011b	;BIT 7=SIDE, LOW NIBBLE=SECTOR
MOTDRV:	DB	0		;DRIVE #(FILLED BY ROUTINE SELDRV)
	DB	00		;STATUS BYTE
	DB	25h		;DJDMA HALT CONTROLLER COMMAND
MOTHLT:	DB	00		;STATUS BYTE

RUNONE: ld	a,(mdflag)	;0=djdma, 1=microdecision
	or	a
	jp	nz,mddrv

;run the djdma controlled motor

	LD	HL,MOTCMD	;START ADDRESS OF BLOCK TRANSFER FROM
	LD	DE,0050h	;START ADDR OF BLOCK TO TRANSFER TO
	LD	BC,07		;NUMBER OF BYTES TO TRANSFER
	LDIR			;DOES THE TRANSFER
	OUT	(0EFh),A	;START THE DJDMA

DONYET:	LD	A,(MOTHLT-MOTCMD+50h);DOES HALT INSTRUCTION STATUS BYTE
	OR	A		;INDICATE INSTRUCTION COMPLETED ?
	JP	Z,DONYET

	RET

;run the microdecision controlled motor

mddrv:	ld	a,(motdrv)	;get the drive number (0-3)
	ld	b,00010000b	;upper four bits will drive drive select lines
mddrv1:	or	a		;see if correct drive has been reached
	jp	z,mdmotr	;correct bit is now set for the selected drive
	dec	a		;try the next drive
	rlc	b		;select next drive higher drive bit
	jp	mddrv1		;loop

mdmotr:	ld	a,(motdrv)	;get the drive number (0-3)
	or	a		;see if drive 0
	ld	a,1		;we're prepared if it is drive 0 
	jp	z,drivon	;go turn on drive 0 motor (bits 0,1 select mtr)
	inc	a		;must be drive 1, 2,or 3 (md wants only 1 or 2)

drivon:	or	b		;add in the drive select line to motor line
	out	(0F7h),a	;turn on selected microdecision drive
	ret


;****************************************************************
;*								*
;*			SUBROUTINE TRKCRT			*
;*								*
;*	1. MOVE CURSOR TO TRACK NUMBER DISPLAY ON CRT		*
;*	2. PRINT THE TWO ASCII TRACK DIGITS ON CRT		*
;*								*
;****************************************************************

TRKCRT:	LD	B,2Ah		;COLUMN ADDRESS (NO OFFSET)
	LD	C,09d		;ROW ADDRESS (NO OFFSET)
	CALL	CURADD		;MOVE CURSOR TO TRACK NUMBER POSITION

	LD	C,6		;BDOS DIRECT CONSOLE I/O
	LD	A,(DIGIT1)
	LD	E,A		;PRINT THE FIRST DIGIT
	CALL	BDOS

	LD	C,6		;BDOS DIRECT CONSOLE I/O
	LD	A,(DIGIT2)	;PRINT THE SECOND DIGIT
	LD	E,A
	CALL	BDOS

	RET


;************************************************************************
;*									*
;*			SUBROUTINE TRKHEX				*
;*									*
;*	CONVERT THE TWO ASCII TRACK DIGITS TO A HEX BYTE AND LOAD IT 	*
;*	INTO THE DJDMA READ SECTOR COMMAND				*
;*									*
;************************************************************************

TRKHEX:	XOR	A
	LD 	(MOTTRK),A	;INITIALIZE AT LOWEST TRACK (0)

	LD	A,(DIGIT1)	;ASCII TENS TRACK DIGIT
	SUB	30h		;NOW HEX TENS TRACK DIGIT
	CP	0
	JP	Z,ONES		;THERE ARE NO TENS
	LD	B,A
	LD	A,(MOTTRK)	;INITIALIZED AT LOWEST TRACK (0)
ADDTEN:	ADD	A,10d
	DJNZ	ADDTEN
	LD	(MOTTRK),A	;TEMPORARY STORAGE

ONES:	LD	A,(DIGIT2)	;ASCII ONES TRACK DIGIT
	SUB	30h		;NOW HEX ONES TRACK DIGIT
	CP	0
	RET	Z		;THERE ARE NO ONES TO ADD
	LD	B,A
	LD	A,(MOTTRK)
ADDONE:	ADD	A,1
	DJNZ	ADDONE
	LD	(MOTTRK),A	;INSERT HEX TRACK NUMBER IN STRING
	LD	(MDTRAK),A	;INSERT HEX TRACK NUMBER IN MICRODEC STRING
	ld	a,(mdflag)	;0=djdma, 1=microdecision
	or	a
	jp	nz,mdseek	;if a microdecision, go do the seek

	RET


;************************************************************************
;*									*
;*			SUBROUTINE MDSEEK				*
;*									*
;*	STEPS THE MICRODECISION CONTROLLED DRIVE HEAD TO THE TRACK	*
;*	SPECIFIED IN BYTE MDTRK.  THE SEEK COMMAND IS A THREE BYTE	*
;*	COMMAND.							*
;*									*
;************************************************************************

MDSEEK:	CALL 	MDSTAT		;GET THE STATUS OF THE 765 CONTROLLER CHIP

	CALL	MDDLY		;DELAY 12.5 uS
	LD	A,0Fh		;NEC 765 SEEK COMMAND CODE
	OUT	(0FBh),A	;SEND SEEK COMMAND TO NEC 765 DATA PORT

	CALL	MDDLY		;DELAY 12.5 uS
	LD	A,0		;BIT 2 SELECTS THE DRIVE HEAD
MDSIDE	EQU	$-1		;FOR CONVENIENT PATCHING BY SUBROUTINE SIDSEL
	OUT	(0FBh),A	;BYTE 2 OF SEEK COMMAND

	CALL	MDDLY		;DELAY 12.5 uS
	LD	A,16		;BYTE 3 SELECTS THE CYLINDER NUMBER (0-39)
MDTRAK	EQU	$-1		;FOR PATCHING BY SUBROUTINE TRKHEX
	OUT	(0FBh),A

;*THE FOLLOWING COMMAND TERMINATES SEEK AND RECALIBRATE COMMANDS*
CALL	MDDLY			;DELAY 12.5 uS
	LD	A,08		;SENSE INTERRUPT STATUS COMMAND(CLEARS FDD0-3)
	OUT	(0FBh),A	;ISSUE THE COMMAND
	IN	A,(0FBh)	;READ STATUS 0
	IN	A,(OFBh)	;READ PRESENT CYLINDER NUMBER

	RET
	

;************************************************************************
;*									*
;*			SUBROUTINE MDSTAT				*
;*									*
;*	READS MICRODECISION PORT 0FAh TO GET THE STATUS OF THE NEC 765	*
;*	CONTROLLER CHIP.						*
;*									*
;************************************************************************

MDSTAT:	CALL 	MDDLY		;DELAY 12.5 uS
	IN	A,(0FAh)	;READ NEC 765 STATUS PORT
	AND	0Fh		;keep lower 4 bits (fdd0-fdd3 busy)
	OR	A
	
	RET


;************************************************************************
;*									*
;*			SUBROUTINE MDDLY				*
;*									*
;*	DELAYS 12 uS.  12uS IS THE MINIMUM TIME REQUIRED BETWEEN BYTES 	*
;*	BEING OUTPUT TO THE NEC 765.  					*
;*		12.5uS = (50 CYCLES)/(4 MHZ)				*
;*									*
;************************************************************************

MDDLY:	EX	(SP),IX		;23 CLOCK CYCLES TO EXECUTE THIS INSTRUCTION
	EX	(SP),IX		;23 MORE CLOCK CYCLES
	RET			; 1 CLOCK CYCLE FOR RET (3 CYCLES FOR CALL)  


	END