;VDPRE - VDDRV PREFIX FILE
;ORIGINAL FROM GLENN EVERHARD (VE)
;Modified by:
;	J.M.Bostwick 29-dec-84
;	JMB205 -- rename to VD, add symbols for use with (modified) 
;		John Cross AVD DVD.
;	
;	J.M.Bostwick  3-JAN-1984 
;	JMB209 -- add cell to extension for private IO count. 
;
;Last Edit:JMB 9-JAN-1985 18:32:48 
;;;O$WNRS=0	;ALLOW PRIVATE PACKS
	.IF	NDF,X..DF.
$M$VD$=0
M$VD$$ = 0 ;MULT VD ASSIGNS
.ENDC

;	.NLIST
	.TITLE	VD     - VIRTUAL DISK PREFIX FILE
;
;	GET UCB OFFSETS.
;
	.MCALL	UCBDF$		;DEFINE UCB OFFSETS
	UCBDF$
;
; DEFINE ADDITIONAL UCB OFFSET.
;

	.IF	NDF,R$$MPL	;FOR RSX11M --------------------------
U.NXT	= U.VCB+2		;EXTENSION BLOCK ADDRESS
	.IFF			;FOR RSX11M+ -------------------------
.IF NDF,R$MPV2 ;FOR RSX11M+ V1
U.NXT	= U.VCB+14		;EXTENSION BLOCK ADDRESS
.IFF ;V2
U.NXT=U.CNT+40
V$$RSN = 77			; KLUGE TO GET MV4.1 CODE, WHICH IS 
				; ALSO FOR M+
.ENDC
	.ENDC			; ------------------------------------
	.IF DF,O$WNRS
U.TIU=U.NXT+2	;TI UCB ADDRESS
U.PWD=U.TIU+2	;ACCESS PASSWORD
	.ENDC

;
; DEFINE EXTENSION BLOCK OFFSETS.
	.IF	NDF,M$VD$$
X.OFF	= 0			;DISK FILE OFFSETS
X.UCB	= X.OFF+4		;NEXT UCB ADDRESS
X.FLG	= X.UCB+2		;EXTENSION FLAGS
X.FNB	= X.FLG+2		;FILENAME BLOCK
X.UIC	= X.FNB+36 		;UIC OF OWNER
X.LABL	= X.UIC+2		;VOLUME LABEL OF HOST DISK
	.IF 	DF,R$$MPL
X.PIOC	= X.LABL+12.		; PRIVATE IO COUNT DOUBLEWORD
X.LGTH	= X.PIOC+4		; LENGTH OF EXTENSION BLOCK
	.IFF	;R$$MPL
X.LGTH	= X.LABL+12.		;LENGTH OF EXTENSION BLOCK
	.ENDC
	.IFF
;
;;
X.FLG=0		;FLAG WORD FIRST (ONLINE/OFFLINE HERE, ALSO RO FLAG)
X.OFF=X.FLG+2
;1ST 2 WORDS= LOW BLK (HI,LO) OF FILE ON DISK
;2ND 2 WORDS= LENGTH (HI,LO) OF FILE
;NEXT WORD (5TH)=UCB
X.NFIL=8.	;MAX NUMBER OF FILES THAT MAY LINK INTO A VIRTUAL DISK UNIT
X.UCB=X.OFF+10	;OFFSET TO 1ST UCB
X.FNB=X.OFF+<10.*X.NFIL>
X.LGTH	= X.FNB+36		;LENGTH OF EXTENSION BLOCK
	.ENDC
;
; DEFINE EXTENSION FLAG BITS
;
XF.RON	= 1			;ALLOW ONLY READ ACCESS
;
; DEFINE VD: AS LOADABLE
LD$VD=0
;
; DEFINE NUMBER OF VD: UNITS    (#UCBs)
	.IF	NDF,X..DF.
V$$D11=14
	.ENDC
$MAXVS = 40. 	; MAX NUMBER OF VS: ASSIGNMENTS TO USE
R$$SOB = 1	; ENABLE SOB INSTRUCTION (???)

	.LIST