;
;   Prefix file for QT: driver and QTA assignment program.
;
APR5	=	120000	; Virtual base of APR 5 mapping.
APR6	=	140000	; Virtual base of APR 6 mapping.
APRMSK	=	160000	; Mask of APR selection bits in virtual address.
MAXMOV	=	4	; Maximum $BLXIO transfer size (in 64 byte blocks).
NUMBUF	=	15.	; Default number of buffers.
SIZBUF	=	4160.	; Default buffer size (big enough for BRU).

	.MCALL	UCBDF$
	UCBDF$
;
;   Define U.CW3 (driver flags) bit definitions.
;
QT.IP	=	1	; Overlapped physical I/O operation in progress.
QT.PO	=	2	; Pending operation delayed by physical operation.
QT.RH	=	4	; Read-ahead halted by error or special condition.
QT.WB	=	10	; Write-behind caching enabled.
QT.WE	=	20	; Write-behind error detected (semi-fatal).
QT.WO	=	40	; Write-behind operation active.
QT.XF	=	100	; Function performs a transfer.

;
;   Define non-standard UCB offsets.
;
	.ASECT
	.=U.VCB+2
U.FBDL:	.BLKW	1	; LIFO free buffer descriptor list.
U.IPKT:	.BLKW	1	; Internal I/O packet address.
U.PHYU:	.BLKW	1	; Physical device UCB address.
U.RALH:	.BLKW	2	; FIFO read-ahead list head.
U.RPCB:	.BLKW	1	; Buffer region PCB address.
U.WBLH:	.BLKW	2	; FIFO write-behind list head.
UCBEND:			; Offset to end of UCB.

;
;   Define read-ahead buffer descriptor offsets.
;
	.=0
BD.LNK:	.BLKW	1	; Link to next buffer descriptor.
BD.ADR:	.BLKW	2	; Buffer address in bias/displacement form.
BD.IOS:	.BLKW	2	; I/O status words.
BD.LEN:	.BLKW	1	; Buffer length in bytes.
BD.SIZ:			; Size of a buffer descriptor.

	.PSECT