.TITLE	NULDRIVER - VAX/VMS Null Printer Device Driver
;
; AUTHOR:
;
;	JY Collot 
;
; REMARQUES :
;
; Cette chose se compile :
;	$ MACRO NULDRIVER
; se linke :
;	$ LINK /NOTRACE NULDRIVER,SYS$INPUT:/OPT
;	BASE=0
; se copie sur SYS$LOADABLE_IMAGES:
; enfin, se charge :
;	$ RUN SYS$SYSTEM:SYSGEN
;	CONNECT NULA0/NOADAPTER/DRIVER=NULDRIVER
;	EXIT

	.SBTTL	External and local symbol definitions

;
; External symbols
;
	.LIBRARY	'SYS$LIBRARY:LIB'
	.LINK		'SYS$SYSTEM:SYS.STB'/SE

	$DCDEF				; Device classes and types
	$DDBDEF
	$DEVDEF				; Device characteristics
	$DYNDEF
	$IODEF				; I/O function codes
	$SSDEF				; System status codes
	$UCBDEF				; Unit control block

					; definitions.

	.SBTTL	Standard tables

;
; Driver prologue table
;

	DPTAB	-				; DPT-creation macro
		END=NUL_END,-			; End of driver label
		ADAPTER=NULL,-			; Adapter type
		UCBSIZE=<UCB$C_LENGTH>,	-	; Length of UCB
		FLAGS=<DPT$M_SMPMOD>,-		; Driver runs SMP
		NAME=NULDRIVER			; Driver name
	DPT_STORE INIT				; Start of load
						; initialization table
	DPT_STORE UCB,UCB$B_FLCK,B,SPL$C_IOLOCK8 ; Device FORK LOCK
	DPT_STORE UCB,UCB$B_DIPL,B,22		; Device interrupt IPL
	DPT_STORE UCB,UCB$W_DEVBUFSIZ,W,-	; Default buffer size
		512

	DPT_STORE REINIT			; Start of reload
						; initialization table
	DPT_STORE UCB,UCB$B_DEVCLASS,B,DC$_LP	; Emulates a printer
	DPT_STORE UCB,UCB$B_DEVTYPE,B,DT$_NULL	; 
	DPT_STORE DDB,DDB$L_DDT,D,NUL$DDT	; Address of DDT
	DPT_STORE UCB,UCB$L_DEVCHAR,L,<-	; Device characteristics
		DEV$M_SHR!-			
		DEV$M_IDV!-			;   input device
		DEV$M_REC!-
		DEV$M_AVL!-			; Available
		DEV$M_ODV>			;   output device
	DPT_STORE UCB,UCB$W_STS,W,-
		<UCB$M_ONLINE>
	DPT_STORE END				; End of initialization
						; tables

;
; Driver dispatch table
;

	DDTAB	-				; DDT-creation macro
		DEVNAM=NUL,-			; Name of device
		FUNCTB=NUL_FUNCTABLE		; FDT address

;
; Function decision table
;

NUL_FUNCTABLE:					; FDT for driver
	FUNCTAB	,-				; Valid I/O functions
		<READVBLK,-			; Read virtual
		READLBLK,-			; Read logical
		READPBLK,-			; Read physical
		WRITEVBLK,-			; Write virtual
		WRITELBLK,-			; Write logical
		WRITEPBLK,-			; Write physical
		SETMODE,-			; Set device mode
		SETCHAR>			; Set device chars.
	FUNCTAB	,				; No buffered functions
	FUNCTAB	FDT_READ,-			; FDT read routine for
		<READVBLK,-			; read virtual,
		READLBLK,-			; read logical,
		READPBLK>
	FUNCTAB FDT_SET,-
		<SETMODE,-
		SETCHAR>			; and read physical.
	FUNCTAB	FDT_WRITE,-			; FDT write routine for
		<WRITEVBLK,-			; write virtual,
		WRITELBLK,-			; write logical,
		WRITEPBLK>			; and write physical.

;++
; FDT_READ
;
;--

FDT_READ:				; Sample FDT routine
	Movl	#SS$_ENDOFFILE,R0
	CLRL	R1
	JMP	G^EXE$ABORTIO

FDT_SET:				; Sample FDT routine
	Movl	#SS$_NORMAL,R0
	CLRL	R1
	JMP	G^EXE$FINISHIO

FDT_WRITE:				; Sample FDT routine
	Movl	#SS$_NORMAL,R0
        INSV	8(ap),#15,#16,R0
	CLRL	R1
	JMP	G^EXE$FINISHIO

;++
; Label that marks the end of the driver
;--

NUL_END:					; Last location in driver
	.END
		FUNCTB=NUL_FUNCTABLE		; FDT address

;
; Function decision table
;

NUL_FUNCTABLE:					; FDT for driver
	FUNCTAB	,-				; Valid I/O functions
		<READVBLK,-			; Read virtual
		READLBLK,-			; Read logical
		READPBLK,-			; Read physical
		WRITEVBLK,-			; Write virtual
		WRITELBLK,-			; Write logical
		WRITEPBLK,-			; Write physical
		SETMODE,-			; Set device mode
		SETCHAR>			; Set device chars.
	FUNCTAB	,				; No buffered functions
	FUNCTAB	FDT_READ,-			; FDT read routine for
		<READVBLK,-			; read virtual,
		READLBLK,-			; read logical,
		READPBLK>
	FUNCTAB FDT_SET,-
		<SETMODE,
		SETCHAR>			; and read physical.
	FUNCTAB	FDT_WRITE,-			; FDT write routine for
		<WRITEVBLK,-			; write virtual,
		WRITELBLK,-			; write logical,
		WRITEPBLK>			; and write physical.

;++
; FDT_READ
;
;--

FDT_READ:				; Sample FDT routine
	Movl	#SS$_ENDOFFILE,R0
	CLRL	R1
	JMP	G^EXE$ABORTIO

FDT_SET:				; Sample FDT routine
	Movl	#SS$_NORMAL,R0
	CLRL	R1
	JMP	G^EXE$FINISHIO

FDT_WRITE:				; Sample FDT routine
	Movl	#SS$_NORMAL,R0
        INSV	8(ap),#15,#16,R0
	CLRL	R1
	JMP	G^EXE$FINISHIO

;++
; Label that marks the end of the driver
;--

NUL_END:					; Last location in driver
	.END