;
;
;
;BOOT - Data Technology Corporation CP/M 2.2 BOOT.
;
;	+-----------------------+
;	|			|
;	|	B O O T 	|
;	|			|
;	+-----------------------+
;
;
;
;	Version number:	2.2B
;	Version date:	March 19, 1981
;
;	Update date:	March 24, 1981
;
;	Update date:	June 26, 1981
;			No longer support boot from single-density
;			diskette.
;
;			Boots from logical unit number in A
;			register on entry.
;
;	The following code is supplied to customers who
;	purchase a hard/floppy disk system from DTC.
;	The following code is written onto track 0 sector 0
;	of the hard disk.  This routine is read into memory
;	at location 0 by the user's PROM.   This routine then
;	loads the rest of the system into memory.
;
;
;	The format of the Hard Disk Boot sectors are as follows:
;
;	Logical		Routine
;	Sector		Name
;
;	  0		Boot program
;
;	1 thru 8	CCP
;
;	9 thru 22	BDOS
;
;	23 thru 32	DTC CBIOS
;
	




VERS:	EQU	22







	


;Enter and exit with A = logical unit # of the boot device


	ORG	100h
BOOT:
	LXI	SP,BOOT
	LXI	H,DT		;Find parameters
	LXI	D,DTELN
	MVI	B,NLUN
BOOT2:
	CMP	M
	JZ	BOOT3
	DAD	D
	DCR	B
	JNZ	BOOT2
	LXI	H,DT
	XRA	A
BOOT3:
	INX	H
	STA	LUN		;Set logical unit number
	STA	CIOAD+1
	STA	CIOFS+1
	MOV	A,M
	STA	CIOPB+3		;Set starting sector
	INX	H
	MOV	A,M
	STA	CIOPB+4		;Set # sectors
	INX	H		;Set drive type
	MOV	A,M
	INX	H
	CPI	0FFh
	JZ	BOOT0
	STA	CIOAD+4
	PUSH	H
	LXI	H,CIOAD
	CALL	EXEC
	CZ	WAITF
	POP	H
BOOT0:
	MOV	A,M
	CPI	0FFh
	JZ	BOOT1
	STA	CIOFS+5
	LXI	H,CIOFS
	CALL	EXEC
	CZ	WAITF
BOOT1:
	LXI	D,CCP
	LXI	H,CIOPB
	CALL	RDISK
	ORA	A
	JNZ	BOOT1
	MOV	A,C
	ANI	FERR
	JNZ	BOOT1

	LDA	LUN
	JMP	CBIOS 


CIOAD:	DB	ADCMD,0,0,0,0,0
CIOFS:	DB	FSCMD,0,0,0,0,0
CIOPB:	DB	RDCMD
LUN:	DB	0

	DB	0,1
	DB	0		;Read two tracks less BOOT
	DB	0		;Perform not retries

BOTSIZ:	EQU	BIOCOD+CBIOS-CCP
HBTLN:	EQU	BOTSIZ/256
FBTLN:	EQU	24+(BOTSIZ-24*128)/256
MBTLN:	EQU	14+(BOTSIZ-14*128)/256

DT:
	IF	LUN0
	DB	0 SHL 5
	DB	1+NF0+N48M0+N96M0
	DB	NH0*HBTLN+NF0*FBTLN+(N48M0+N96M0)*MBTLN
	DB	LUN0DAT
	DB	B0
	ENDIF
	IF	LUN1
	DB	1 SHL 5
	DB	1+NF1+N48M1+N96M1
	DB	NH1*HBTLN+NF1*FBTLN+(N48M1+N96M1)*MBTLN
	DB	LUN1DAT
	DB	B1
	ENDIF
	IF	LUN2
	DB	2 SHL 5
	DB	1+NF2+N48M2+N96M2
	DB	NH2*HBTLN+NF2*FBTLN+(N48M2+N96M2)*MBTLN
	DB	LUN2DAT
	DB	B2
	ENDIF
	IF	LUN3
	DB	3 SHL 5
	DB	1+NF3+N48M3+N96M3
	DB	NH3*HBTLN+NF3*FBTLN+(N48M3+N96M3)*MBTLN
	DB	LUN3DAT
	DB	B3
	ENDIF
DTELN:	EQU	5
DTLEN:	EQU	($-DT)/DTELN

;	Disk I/O Routines
;
;
	IF	I696
;	E X E C

EXEC:	MVI	B,BUSY		;Wait for not busy.
	MVI	C,BUSY and (not BUSY)
	CALL	WAITM
	RNZ
	

	MVI	A,SLCT		;Alert controller
	OUT	DIO+1
EXEC1:
	MOV	C,B		;Wait for controller busy
	CALL	WAITM
	RNZ

	MVI	A,DODTA		;Enable data in
	OUT	DIO+1

EXEC2:	IN	DIO+2		;Get status
	XRI	0FFh
	JM	EXEC2		;If not requesting next byte
	ANI	CMND+DIROUT
	JNZ	EXEC3		;If CMND or DIROUT false
	MOV	A,M
	INX	H
	OUT	DIO		;Send byte from command buffer
	JMP	EXEC2

EXEC3:	CMP	A		;Z:=1
	RET
;
;
;
;
;	RDISK - Input to memory buffer.
;
;	Entry:	HL = command buffer address
;		DE = data buffer address

RDISK:	CALL	EXEC
	RNZ			;Return if timeout
RDISK1:	IN	DIO+2		;Read status
	ORA	A
	JP	RDISK1		;If request is present
	ANI	CMND
	JNZ	GCMPS
	IN	DIO
	STAX	D
	INX	D
	JMP	RDISK1
;
;
;
;
;	WAITF - Wait for function to complete.

WAITF:	MVI	B,REQ+CMND	;Wait for both REQ and CMND
	MOV	C,B
	CALL	WAITM
	RNZ
;
;	Get completion status.

GCMPS:	IN	DIO		;Get completion status
	MOV	C,A

GCMP1:	IN	DIO+2
	ORA	A
	JP	GCMP1		;If REQ not set

	MOV	B,A
	IN	DIO		;Get message byte
	RET
	ENDIF
;

;
;
;
	IF	I796
;	EXEC - Output the command
;
;	Enter:	HL is the command buffer address
;		DE - data transfer address.

EXEC:
	MOV	A,E		;Output DMA address
	OUT	DIO+2
	MOV	A,D
	OUT	DIO+3
	MOV	A,L
	OUT	DIO+4
	MOV	A,H
	OUT	DIO+5
	MVI	A,0
	OUT	DIO+6
	OUT	DIO+7
	OUT	DIO
	CMP	A		;Z:=1
	RET


;	Disk read/write
;
;	Entry:	same as EXEC
;
RDISK:
WDISK:	CALL	EXEC
	RNZ			;Return if timeout

;	WAITF - Wait until transfer done
;
;	Enter:	none
;	Exit:	when transfer completed

WAITF:	MVI	B,CMDDON	;Wait for CMDDON
	MOV	C,B
	CALL	WAITM
	RNZ			;Return if timeout
;

;	GCMPS - Get completion status
;
;	Enter:	none
;	Exit:	Status in C
GCMPS:	IN	DIO+1
	MOV	C,A
	RET
	ENDIF

;	WAITM - Wait for controller with timeout
;
;	Entry:	B=Status mask
;		C=Status value
;	Exit:	Z=1 if OK, else timeout with A=C=TERR
;
WAITM:
	PUSH	D		;Save D
	PUSH	H
	LXI	H,138		;Two minute timeout
	LXI	D,0		;Max wait @4MHZ is 868 ms
WAITML:
	IF	I696
	IN	DIO+2
	ENDIF
	IF	I796
	IN	DIO
	ENDIF
	ANA	B		;Mask wait bits
	CMP	C		;Check value
	JZ	WAITM1
	DCX	D		;Not ready.  Decrement time
	MOV	A,D
	ORA	E
	JNZ	WAITML
	DCX	H
	MOV	A,H
	ORA	L
	JNZ	WAITML
	MVI	B,0		;Timeout
	MVI	A,TERR
	ORA	A
WAITM1:
	POP	H
	POP	D		;Restore D
	MOV	C,A		;Return status in C
	RET


	END