DBDRV.MAC/AU:72.=DBDRV32.MAC/-BF
-2,2,/;DM001/
	.IDENT	/5.04D/
-11,11,/;DM001/
; VERSION 5.04D
-16,,/;DM001/
;	D. S. MCCOY     Informatics Inc., Palo Alto, Ca.
-71,,/;DM001/
;	D. S. MCCOY 21-DEC-79    INFORMATICS INC, PALO ALTO, CA.
;
;		DM001 -- ADDED DUAL-CONTROLLER ARBITRATION.
;			 BASED ON A COMBINATION OF THE M-PLUS DRIVER
;			 AND A VERSION BY C. L. WILDES, T. G. WILHITE
;			 OF DEC CSS, SANTA ANA.  USED THE CSS LOGIC,
;			 BUT STORE STATUS WHERE BEZEREDI DID IN THE
;			 M-PLUS DRIVER.
;
-91,,/;DM001/
IE=100				; INTERRUPT ENABLE BIT
-113,,/;DM001/
DPR=400				; DRIVE PRESENT ON PORT BIT
-171,,/;DM001/
SEL=20				; PORT SELECT WAIT FLAG (1=WAITING)
-391,393,/;DM001/
	BICB	#SEL,U.CW2+1(R5) ;CLEAR PORT SELECT WAIT FLAG
	ADD	#10,R2		;POINT TO SECOND CSR
	MOV	#40,(R2)	;CLEAR RH11 CONTROLLER AND ALL DRIVES
	MOVB	U.UNIT(R5),(R2)	;SELECT PROPER DRIVE

	CLR	RPDS-RPCS2(R2)	; ATTEMPT TO SIEZE THE DRIVE
	BIT	#DPR,RPDS-RPCS2(R2) ; DID IT SIEZE?
	BNE	43$		; IF NE, WE SIEZED IT
	BISB	#SEL,U.CW2+1(R5) ; SET PORT SELECT WAIT FLAG
	MOV	#IE,RPCS1-RPCS2(R2) ; ENABLE CONTROLLER INTERRUPTS
	RETURN		; WAIT FOR ATTENTION INTERRUPT

43$:			; REF LABEL
-471,471,/;DM001/
	JMP	76$		;FINISH UP AND RELEASE DRIVE
-543,,/;DM001/
	BITB	#SEL,U.CW2+1(R5) ; WAITING FOR PORT SELECT?
	BEQ	52$		; IF EQ, NO
	BIT	#TRE!MCPE,(R2)	; ANY HARD ERRORS?
	BNE	53$		; IF NE, YES
	MOV	#IE.DNR&377,R0	; ASSUME DRIVE NOT READY
	BIT	#DPR,RPDS(R2)	; DRIVE PRESENT ON PORT?
	BNE	56$		; IF NE, YES, RESTART I/O
	JMP	70$		; FAILURE TO SIEZE DRIVE, ERROR
52$:			; REF LABEL
-565,,/;DM001/
53$:		; REF LABEL
-597,597,/;DM001/
	BNE	62$		;IF NE YES				; RP004
-640,,/;DM001/
	MOV	U.CW2(R5),-(SP) ; SAVE FLAGS
	BICB	#SEL,U.CW2+1(R5) ; CLEAR PORT SELECT WAIT FLAG
	SWAB	(SP)		; GET FLAGS IN LOW BYTE
	BIT	#SEL,(SP)+	; CHECK PORT SELECT WAIT FLAG
	BEQ	61$		; IF EQ, WE WERE NOT WAITING
	DECB	RTTBL(R3)	; DEC RETRY COUNT
	CMPB	RTTBL(R3),#RETRY-4 ; TRIED 4 TIMES (16 SECONDS)?
	BLT	70$		; IF LT, YES - FINISH WITH IE.DNR SET
	JMP	40$		; TRY AGAIN
61$:			; REF LABEL
-648,650,/;DM001/
	BEQ	62$		;IF EQ NO				; RP004
	JMP	185$		;CONTINUE OFFSET RECOVERY		; RP004
62$:	DECB	RTTBL(R3)	;RETRY FUNCTION?			; RP004
-700,,/;DM001/
75$:	TSTB	(R2)		; CONTROLLER AND DRIVE READY?
	BPL	75$		; IF PL, NO
76$:	MOV	#13,(R2)	; RELEASE DRIVE FROM PORT
/