;
;	FORMAT UTILITY FOR COMMODORE 64   CP/M
;
;	COPYRIGHT (C) 1982
;       COMMODORE INTERNATIONAL
;
;
;	EQUATES
;
BOOT	EQU	0000H	;RESTART VECTOR
BDOS	EQU	0005H	;BDOS ENTRY POINT
CMD	EQU	0F900H	;COMMAND REGISTER
DATA	EQU	0F901H	;STATUS REGISTER
SECTOR	EQU	0F902H	;SECTOR REGISTER
TRACK	EQU	0F903H	;TRACK REGISTER
DISKNO	EQU	0F904H	;DISK NUMBER
BUFFER 	EQU	0F800H	;SECTOR BUFFER
VICWR	EQU	1	;WRITE COMMAND
VICFMT	EQU	6	;FORMAT COMMAND
OFF	EQU	1	;Z80 TURN-OFF DATA
MODESW	EQU	0CE00H	;Z80 TURN-OFF ADDRESS
NIMAGE	EQU	0400H	;NORMAL FORMAT DATA IMAGE
SIMAGE	EQU	2000H	;SPECIAL FORMAT DATA IMAGE
;
;
	ORG	0100H		;START OF TPA
;
	LXI	SP,STACK	;SET LOCAL STACK
	LXI	D,NAME	
	CALL	PRINT		;PRINT TITLE MESSAGE
;
	MVI	A,0
	STA	DISKNO		;SELECT DRIVE 0
;
;
LOOP:	LXI	SP,STACK	;READJUST STACK POINTER
	LXI	D,INSMSG	;INSERT DISK MESSAGE
	CALL	PRINT
;
CIN:	CALL	CONIN		;GET NEXT KEYBOARD CHARACTER
	CPI	0DH		;IS IT CARRIAGE RETURN?
	JZ	NORMAL		;NORMAL FORMAT
;
	CPI	03H		;IS IT RUN/STOP KEY?
	JZ	BOOT
;
	CPI	'*'		;IS IT '*'?
	JZ	SPCL		;SPECIAL FORMAT
;
	JMP	CIN		;ELSE TRY AGAIN
;
NORMAL:	CALL	FORMAT		;DO 1540 FORMAT FIRST
	LXI	H,NIMAGE		;NORMAL FORMAT DATA STARTS HERE
	CALL	WRSYS		;WRITE SYSTEM TRACKS
	JMP	AGAIN
;
SPCL:	CALL	FORMAT		;DO 1540 FORMAT FIRST
	LXI	H,SIMAGE		;SPECIAL FORMAT DATA IS PLACED
	CALL	WRSYS		;  HERE BY USER
;
AGAIN:	LXI	D,DONE		;REMOVE DISK MESSAGE
	CALL	PRINT
;
AGAIN0:	LXI	D,CONT		;PRESS SPACE MESSAGE
	CALL	PRINT
;
AGAIN1:	CALL	CONIN		;WAIT FOR SPACE BAR
	CPI	' '
	JNZ	AGAIN1
;
	JMP	LOOP
;
FORMAT:	LXI	D,FMTMSG
	CALL	PRINT
;
	MVI	A,VICFMT	;FORMAT COMMAND
	STA	CMD
	MVI	A,OFF		;TURN OFF Z80
	STA	MODESW
	NOP
	LDA	DATA		;DATA=0 IF OK
	ANA	A
	JNZ	ERROR
	RET
;
WRSYS:	MVI	A,0	;WRITE SYSTEM TRACKS
	STA	DISKNO
;
	PUSH	H	;SAVE POINT
	MVI	A,1
	STA	TRACK
;
	MVI	A,0
	STA	SECTOR
;
	CALL	WRSEC	;DO FAKE WRITE
	POP	H	;GET READY FOR REAL THING
;
	MVI	A,1
	STA	TRACK
;
	MVI	A,0
WRSYS1:	STA	SECTOR
;
	CALL	WRSEC
;
	LDA	SECTOR	;TRACK 1, SECTORS 0-4
	INR	A
	CPI	5
	JC	WRSYS1	;CY=1 IF A<5
;
	MVI	A,18
	STA	TRACK	;DIRECTORY TRACK
	MVI	A,0
WRSYS2:	STA	SECTOR
;
	CALL	WRSEC
;
	LDA	SECTOR	;TRACK 18, SECTORS 0-1
	INR	A
	CPI	2
	JC	WRSYS2	;CY=1 IF A<2
;
	LXI	H,BUFFER
	MVI	A,0E5H		;BLANK DIRECTORY DATA
WRDIR0:	MOV	M,A
	INR	L
	JNZ	WRDIR0		;256 TIMES
;
	MVI	A,3
	STA	TRACK
	MVI	A,0
WRDIR1:	STA 	SECTOR
	MVI	A,VICWR
	STA	CMP
	MVI	A,OFF
	STA	MODESW
	NOP
	LDA	DATA
	ANA	A
	JNZ	ERROR
;
	LDA	SECTOR
	INR	A
	CPI	8
	JC	WRDIR1	;TRACK3,SECTORS 0-7
;
	RET	;DONE WITH SYSTEM TRACKS
;
WRSEC:	MVI	D,BUFFER/256	;DE POINTS TO SECTOR BUFFER
	MVI	E,0
;
WR1:	MOV	A,M		;GET NEXT DATA BYTE
	STAX	D		;PUT IN BUFFER
	INX	H		;NEXT DATA
	INR	E		;NEXT BUFFER
	JNZ	WR1		;UNTIL E=0
;
	MVI	A,VICWR		;SET UP WRITE COMMAND
	STA	CMD
	MVI	A,OFF
	STA	MODESW
	NOP
	LDA	DATA	;DATA=0 IF NO ERROR
	ANA	A
	JNZ	ERROR
	RET
;
ERROR:	LXI	D,ERRMSG
	CALL	PRINT
;
	JMP	AGAIN0	;WAIT FOR SPACE AND CONTINUE
;
PRINT:
	MVI	C,9	;PRINT FUNCTION #
	CALL	BDOS
	RET
;
CONIN:	MVI	C,6	;DIRECT CONSOLE I/O #
	MVI	E,0FFH	;INPUT MODE
	CALL	BDOS
	RET
;
;
;	MESSAGES
;
NAME:	DB	0DH,0DH,'Commodore 64 CP/M Format Utility 1.0'
	DB	0DH,0DH,'$'
;
INSMSG:	DB	'Insert disk to be formatted into ',0DH
	DB	'  drive A and close door.',0DH,0DH
	DB	'Press RETURN key to format (or RUN/STOP',0DH
	DB	'  key to reboot system)',0DH,0DH,'$'
;
FMTMSG:	DB	'FORMATTING DISKETTE.  PLEASE WAIT...',0DH,0DH,'$'
;
ERRMSG:	DB	'I cannot format this disk!',0DH,0DH,'$'
;
DONE:	DB	'FORMAT complete.  Please remove disk.',0DH,0DH,'$'
;
CONT:	DB	'Press SPACEBAR to continue',0DH,0DH,'$'
	DS	64	;SPACE FOR STACK
STACK 	EQU	$