DCB for BTAM and QTAM

Common Name:

Data Control Block for BTAM and QTAM

Macro Name:

DCBD

DSECT Name:

IHADCB

Owning Component:

Data Management, subcomponent OPEN/CLOSE/EOV

Eye-Catcher ID:

None

Subpool and Key:

Problem program subpool and key

Size:

Variable up to 100 bytes

Created by:

Problem program

Pointed to by:

DEBDCBAD field of the DEB data area
IOBDCBPT field of the IOB data area
DECDCBAD field of the DECB data area (BDAM, BSAM, and BTAM DCBs)

Serialization:

None

Function:

This data control block (DCB) describes data sets being processed by the basic telecommunications access method (BTAM) and data sets being processed by the queued telecommunications access method (QTAM). All DCB formats share the same interface and foundation extension.

Offset	Type/Value	Len	Name (Dim)	Description
DATA CONTROL BLOCK DEFINITION
	X'80'		DCBBIT0	"128"
	X'40'		DCBBIT1	"64"
	X'20'		DCBBIT2	"32"
	X'10'		DCBBIT3	"16"
	X'8'		DCBBIT4	"8"
	X'4'		DCBBIT5	"4"
	X'2'		DCBBIT6	"2"
	X'1'		DCBBIT7	"1"
DEVICE INTERFACES WORLD TRADE TELEGRAPH
16 (10)	BITSTRING	1	DCBBQFLG	– WTTA FLAG BYTE
	.1. . . . . .		DCBBQWRU	"DCBBIT1"– WRU FEATURE IS TO BE USED
	. .1. . . . .		DCBBQIAM	"DCBBIT2"– IAM FEATURE IS TO BE USED
	. . .1 . . . .		DCBBQWRS	"DCBBIT3"– WRU FEATURE TO BE USED IN SEND HEADER SUBGROUP
	. . . . 1. . .		DCBBQWRE	"DCBBIT4"– WRU FEATURE TO BE USED IN END SEND SUBGROUP
17 (11)	CHARACTER	1	DCBWTEOM	– EOM CHARACTER
18 (12)	CHARACTER	1	DCBWTEOT	– EOT CHARACTER
19 (13)	SIGNED	1	DCBWTPAD	– NUMBER OF PAD (LTRS) CHARACTERS REQUIRED FOR MOTOR-ON DELAY
BTAM LINE GROUP INTERFACE
20 (14)	ADDRESS	4	DCBBUFCB (0)	– ADDRESS OF BUFFER POOL CONTROL BLOCK
20 (14)	SIGNED	1	DCBBUFNO	– NUMBER OF BUFFERS OBTAINED BY OPEN
21 (15)	ADDRESS	3	DCBBUFCA	– ADDRESS OF BUFFER POOL CONTROL BLOCK
24 (18)	SIGNED	2	DCBBUFL	– BUFFER LENGTH
26 (1A)	BITSTRING	2	DCBDSORG (0)	– DATA SET ORGANIZATION BEING USED
26 (1A)	BITSTRING	1	DCBDSRG1	– FIRST BYTE OF DCBDSORG
	1. . . . . . .		DCBDSGIS	"DCBBIT0"– IS – INDEXED SEQUENTIAL ORGANIZATION
	.1. . . . . .		DCBDSGPS	"DCBBIT1"– PS – PHYSICAL SEQUENTIAL ORGANIZATION
	. .1. . . . .		DCBDSGDA	"DCBBIT2"– DA – DIRECT ORGANIZATION
	. . .1 . . . .		DCBDSGCX	"DCBBIT3"– CX – BTAM OR QTAM LINE GROUP
	. . . . . .1.		DCBDSGPO	"DCBBIT6"– PO – PARTITIONED ORGANIZATION
	. . . . . . .1		DCBDSGU	"DCBBIT7"– U – UNMOVABLE, THE DATA CONTAINS LOCATION DEPENDENT INFORMATION
27 (1B)	BITSTRING	1	DCBDSRG2	– SECOND BYTE OF DCBDSORG
1	1. . . . . . .		DCBDSGGS	"DCBBIT0"– GS – GRAPHICS ORGANIZATION
	.1. . . . . .		DCBDSGTX	RESERVED
	. .1. . . . .		DCBDSGTQ	RESERVED
	. . . . 1. . .		DCBACBM	"DCBBIT4"– ACCESS METHOD CONTROL BLOCK
	. . . . .1. .		DCBDSGTR	RESERVED
28 (1C)	ADDRESS	4	DCBIOBAD (0)	– BASE FOR ADDRESSING IOB'S (BASE = ADDRESS OF FIRST IOB MINUS LENGTH OF AN IOB)
28 (1C)	SIGNED	1	DCBDEVTP	– INDEX TO DEVICE ENTRY IN THE DEVICE I/O DIRECTORY
29 (1D)	ADDRESS	3	DCBIOBAA	–- SAME AS DCBIOBAD ABOVE
32 (20)	BITSTRING	1	DCBHIARC (0)	– HIERARCHY FLAG BITS
32 (20)	BITSTRING	1	DCBBFTEK	– BUFFERING TECHNIQUE FLAG BITS
	1. . . . . . .		DCBH1	"DCBBIT0"– HIERARCHY 1 MAIN STORAGE – BIT 5 IS ZERO
	.111 . . . .		DCBBFT	"DCBBIT1+DCBBIT2+DCBBIT3" BUFFERING TECHNIQUE
	.11. . . . .		DCBBFTA	"DCBBIT1+DCBBIT2"– QSAM LOCATE MODE PROCESSING OF SPANNED RECORDS – OPEN IS TO CONSTRUCT A RECORD AREA IF IT AUTOMATICALLY CONSTRUCTS BUFFERS
	. .1. . . . .		DCBBFTR	"DCBBIT2"– FOR BSAM CREATE BDAM PROCESSING OF UNBLOCKED SPANNED RECORDS – SOFTWARE TRACK OVERFLOW. FOR BSAM INPUT PROCESSING OF UNBLOCKED SPANNED RECORDS
	.1. . . . . .		DCBBFTS	"DCBBIT1"– SIMPLE BUFFERING – BIT 3 IS ZERO
	. .1. . . . .		DCBBFTKR	"DCBBIT2"– UNBLOCKED SPANNED RECORDS – SOFTWARE TRACK OVERFLOW (BDAM)
	. . .1 . . . .		DCBBFTE	"DCBBIT3"– EXCHANGE BUFFERING – BIT 1 IS ZERO
	. . . . 1. . .		DCBBFTKD	"DCBBIT4"– DYNAMIC BUFFERING (BTAM)
	. . . . 1. . .		DCBBFTK	"DCBBIT4"– LRECL IN 'K' UNITS FOR XLRI
	.11. 1. . .		DCBBXLRI	"DCBBIT1+DCBBIT2+DCBBIT4"– EXTENDED LOGICAL RECORD INTERFACE MODE FOR SPANNED RECORDS GREATER THAN 32K – ALL RECORDS TRANSFERRED TO OR FROM THE RECORD AREA.
	. . . . .1. .		DCBH0	"DCBBIT5"– HIERARCHY 0 MAIN STORAGE – BIT 0 IS ZERO
	. . . . . .11		DCBBFA	"DCBBIT6+DCBBIT7"– BUFFER ALIGNMENT
	. . . . . .1.		DCBBFAD	"DCBBIT6"– DOUBLEWORD BOUNDARY
	. . . . . . .1		DCBBFAF1	"DCBBIT7"– FULLWORD NOT A DOUBLEWORD BOUNDARY, CODED IN DCB MACRO INSTRUCTION
	. . . . . .11		DCBBFAF2	"DCBBIT6+DCBBIT7"– FULLWORD NOT A DOUBLEWORD BOUNDARY, CODED IN DCB MACRO INSTRUCTION
33 (21)	BITSTRING	1	DCBERROP	– ERROR RECOVERY PROCEDURE BITS
34 (22)	SIGNED	1	DCBBUFCT	– MAX NUMBER OF READ BUFFERS
35 (23)	BITSTRING	1		– RESERVED
36 (24)	ADDRESS	4	DCBEXLST (0)	– ADDRESS OF USER–PROVIDED EXIT LIST
36 (24)	SIGNED	1	DCBEIOBX	– SIZE OF IOB
37 (25)	ADDRESS	3	DCBEXLSA	– ADDRESS OF USER–PROVIDED EXIT LIST
33 (21)	BITSTRING	1	DCBERROP	– ERROR RECOVERY PROCEDURE BITS
	. . .1 . . . .		DCBERPT	"DCBBIT3"– ON–LINE TEST FACILITIES TO BE USED
	. . . . 1. . .		DCBERPC	"DCBBIT4"– THRESHOLD AND CUMULATIVE ERROR COUNTS TO BE MAINTAINED
	. . . . .1. .		DCBERPW	"DCBBIT5"– TEXT-WRITE ERRORS TO BE RETRIED
	. . . . . .1.		DCBERPR	"DCBBIT6"– TEXT–READ ERRORS TO BE RETRIED
	. . . . . . .1		DCBERPN	"DCBBIT7"– IF ZERO, BASIC ERP TO BE FOLLOWED --- IF ONE, NO ERP TO BE FOLLOWED
34 (22)	SIGNED	1	DCBBUFCT	– CONTAINS MAXIMUM NUMBER OF BUFFERS TO BE OBTAINED BY BTAM FOR READ OPERATION (DYNAMIC BUFFERING ONLY)
QTAM LINE GROUP INTERFACE
20 (14)	ADDRESS	4	DCBCLPS (0)	– ADDRESS OF LINE PROCEDURE SPECIFICATION ROUTINE
20 (14)	SIGNED	1	DCBBUFRQ	– NUMBER OF BUFFERS REQUESTED FOR A READ OR WRITE OPERATION
21 (15)	ADDRESS	3	DCBCLPSA	– SAME AS DCBCLPS ABOVE
24 (18)	SIGNED	1	DCBINTVL	– NUMBER OF SECONDS OF INTENTIONAL DELAY BETWEEN PASSES THROUGH A POLLING LIST FOR NONSWITCHED LINES
25 (19)	BITSTRING	1		– RESERVED
26 (1A)	BITSTRING	2	DCBDSORG(0)	– DATA SET ORGANIZATION
26 (1A)	BITSTRING	1	DCBDSRG1	– FIRST BYTE OF DCBDSORG
27 (1B)	BITSTRING	1	DCBDSRG2	– SECOND BYTE OF DCBDSORG
28 (1C)	ADDRESS	1	DCBDEVTP	– DEVICE TYPE POINTER
29 (1D)	ADDRESS	3	DCBIOBAA	– ADDRESS OF FIRST IOB
32 (20)	ADDRESS	4	DCBLCBAD (0)	–BASE FOR ADDRESSING LCB'S (BASE = ADDRESS OF FIRST LCB MINUS LENGTH OF ONE LCB)
32 (20)	BITSTRING	1	DCBCPRI	– COMMUNICATION PRIORITY BITS
	. . . . .1. .		DCBCPR	"DCBBIT5"– RECEIVING HAS PRIORITY
	. . . . . .1.		DCBCPE	"DCBBIT6"– RECEIVING AND SENDING HAVE EQUAL PRIORITY
	. . . . . . .1		DCBCPS	"DCBBIT7"– SENDING HAS PRIORITY
33 (21)	2.ADDRESS	3	DCBLCBA	– SAME AS DCBLCBAD ABOVE
36 (24)	SIGNED	1	DCBEIOBX	– EXTENDED IOB INDEX. SIZE OF LCB.
37 (25)	ADDRESS	3	DCBEXLSA	– ADDRESS OF EXIT LIST
FOUNDATION BEFORE OPEN
40 (28)	CHARACTER	8	DCBDDNAM	– NAME ON THE DD STATEMENT WHICH DEFINES THE DATA SET ASSOCIATED WITH THIS DCB
48 (30)	BITSTRING	1	DCBOFLGS	– FLAGS USED BY OPEN ROUTINE
	1. . . . . . .		DCBOFLWR	"DCBBIT0"– IF ZERO, LAST I/O OPERATION WAS READ OR POINT. IF ONE, LAST I/O OPERATION WAS WRITE.
	1. . . . . . .		DCBOFIOD	"DCBBIT0"– DATA SET IS BEING OPENED FOR INPUT OR OUTPUT (BDAM)
	.1. . . . . .		DCBOFLRB	"DCBBIT1"– LAST I/O OPERATION WAS IN READ BACKWARD MODE
	. .1. . . . .		DCBOFEOV	DCBBIT2"– 1 BY EOV WHEN IT CALLS CLOSE ROUTINE FOR CONCATENATION OF DATA SETS WITH UNLIKE ATTRIBUTES
	. . .1 . . . .		DCBOFOPN	"DCBBIT3"– AN OPEN HAS BEEN SUCCESSFULLY COMPLETED
	. . . . 1. . .		DCBOFPPC	"DCBBIT4"– SET TO 1 BY PROBLEM PROGRAM TO INDICATE A CONCATENATION OF UNLIKE ATTRIBUTES
	. . . . .1. .		DCBOFTM	"DCBBIT5"– TAPE MARK HAS BEEN READ
	. . . . . .1.		DCBOFUEX	"DCBBIT6"– SET TO 0 BY AN I/O SUPPORT FUNCTION WHEN THAT FUNCTION TAKES A USER EXIT. SET TO 1 ON RETURN FROM USER EXIT TO THE I/O SUPPORT FUNCTION WHICH TOOK THE EXIT.
	. . . . . . .1		DCBOFIOF	"DCBBIT7"– SET TO 1 BY AN I/O SUPPORT FUNCTION IF DCB IS TO BE PROCESSED BY THAT FUNCTION
49 (31)	BITSTRING	1	DCBIFLG	– FLAGS USED BY IOS IN COMMUNICATING ERROR CONDITIONS AND IN DETERMINING CORRECTIVE PROCEDURES
	11. . . . . .		DCBIBEC	"DCBBIT0+DCBBIT1"– ERROR CORRECTION INDICATOR
	. . . . . . . .		DCBIFNEP	"X'00'"– NOT IN ERROR PROCEDURE
	.1. . . . . .		DCBEX	"DCBBIT1"– ERROR CORRECTION OR IOS PAGE FIX IN PROCESS
	11. . . . . .		DCBIFPEC	"DCBBIT0+DCBBIT1"– PERMANENT ERROR CORRECTION
1	. .11 . . . .		DCBIBPCT	"DCBBIT2+DCBBIT3"– PRINTER CARRIAGE TAPE PUNCH INDICATOR
	. .1. . . . .		DCBIFC9	"DCBBIT2"– CHANNEL 9 PRINTER CARRIAGE TAPE PUNCH SENSED
	. . .1 . . . .		DCBIFC12	"DCBBIT3"– CHANNEL 12 PRINTER CARRIAGE TAPE PUNCH SENSED
	. . . . 11. .		DCBIBIOE	"DCBBIT4+DCBBIT5"– IOS ERROR ROUTINE USE INDICATOR
	. . . . . . . .		DCBIFER	"X'00'"– ALWAYS USE I/O SUPERVISOR ERROR ROUTINE
	. . . . .1. .		DCBIFNE1	"DCBBIT5"– NEVER USE I/O SUPERVISOR ERROR ROUTINE
	. . . . .1. .		DCBIFTIM	"DCBBIT5"– TEST IOS MASK (IMSK) FOR ERROR PROCEDURE (BTAM)
	. . . . 1. . .		DCBIFNE2	"DCBBIT4"– NEVER USE I/O SUPERVISOR ERROR ROUTINE
	. . . . 11. .		DCBIFNE3	"DCBBIT4+DCBBIT5"– NEVER USE I/O SUPERVISOR ERROR ROUTINE
50 (32)	BITSTRING	2	DCBMACR (0)	– MACRO INSTRUCTION REFERENCE
50 (32)	BITSTRING	1	DCBMACR1	– FIRST BYTE OF DCBMACR
	1. . . . . . .		DCBMRECP	"DCBBIT0"– EXECUTE CHANNEL PROGRAM (EXCP) --- ALWAYS ZERO (BSAM, QSAM, BPAM, BISAM, QISAM, BDAM) --- RESERVED (QTAM, BTAM)
	.1. . . . . .		DCBMRFE	"DCBBIT1"– FOUNDATION EXTENSION IS PRESENT (EXCP)
	.1. . . . . .		DCBMRGET	"DCBBIT1"– GET (QSAM, QISAM)
	.1. . . . . .		DCBMRPTQ	"DCBBIT1"– PUT FOR MESSAGE GROUP (QTAM) --- ALWAYS ZERO (BSAM, BPAM, BISAM, BDAM) --- RESERVED (BTAM)
	. .1. . . . .		DCBMRAPG	"DCBBIT2"– APPENDAGES ARE REQUIRED (EXCP)
	. .1. . . . .		DCBMRRD	"DCBBIT2"– READ (BSAM, BPAM, BISAM, BDAM, BTAM)
	. .1. . . . .		DCBMRWRQ	"DCBBIT2"– WRITE FOR LINE GROUP (QTAM) --- ALWAYS ZERO (QSAM, QISAM)
	. . .1 . . . .		DCBMRCI	"DCBBIT3"– COMMON INTERFACE (EXCP)
	. . .1 . . . .		DCBMRMVG	"DCBBIT3"– MOVE MODE OF GET (QSAM, QISAM)
	. . .1 . . . .		DCBMRRDK	"DCBBIT3"– KEY SEGMENT WITH READ (BDAM) --- ALWAYS ZERO (BISAM) --- RESERVED (BSAM, BPAM, QTAM, BTAM)
	. . . . 1. . .		DCBMRLCG	"DCBBIT4"– LOCATE MODE OF GET (QSAM, QISAM)
	. . . . 1. . .		DCBMRRDI	"DCBBIT4"– ID ARGUMENT WITH READ (BDAM) --- ALWAYS ZERO (BISAM) --- RESERVED (EXCP, BSAM, BPAM, QTAM, BTAM)
	. . . . .1. .		DCBMRABC	"DCBBIT5"– USER'S PROGRAM MAINTAINS ACCURATE BLOCK COUNT (EXCP)
	. . . . .1. .		DCBMRPT1	"DCBBIT5"– POINT (WHICH IMPLIES NOTE) (BSAM, BPAM)
	. . . . .1. .		DCBMRSBG	"DCBBIT5"– SUBSTITUTE MODE OF GET (QSAM)
	. . . . .1. .		DCBMRDBF	"DCBBIT5"– DYNAMIC BUFFERING (BISAM, BDAM) --- ALWAYS ZERO (QISAM) --- RESERVED (QTAM, BTAM)
	. . . . . .1.		DCBPGFXA	"DCBBIT6"– PAGE FIX APPENDAGE IS SPECIFIED (EXCP)
	. . . . . .1.		DCBMRCRL	"DCBBIT6"– CNTRL (BSAM, QSAM)
	. . . . . .1.		DCBMRCHK	"DCBBIT6"– CHECK (BISAM)
	. . . . . .1.		DCBMRRDX	"DCBBIT6"– READ EXCLUSIVE (BDAM) --- RESERVED (BPAM, QISAM, QTAM, BTAM)
	. . . . . . .1		DCBMRDMG	"DCBBIT7"– DATA MODE OF GET (QSAM)
	. . . . . . .1		DCBMRCK	"DCBBIT7"– CHECK (BDAM) --- RESERVED (EXCP, BSAM, BPAM, BISAM, QISAM, QTAM, BTAM)
51 (33)	BITSTRING	1	DCBMACR2	– SECOND BYTE OF DCBMACR
	1. . . . . . .		DCBMRSTL	"DCBBIT0"– SETL (QISAM) --- ALWAYS ZERO (BSAM, QSAM, BPAM, BISAM, BDAM) --- RESERVED (EXCP, QTAM, BTAM)
	.1. . . . . .		DCBMRPUT	"DCBBIT1"– PUT (QSAM) - PUT OR PUTX (QISAM)
	.1. . . . . .		DCBMRGTQ	DCBBIT1"– GET FOR MESSAGE GROUP (QTAM) --- ALWAYS ZERO (BSAM, BPAM, BISAM, BDAM) --- RESERVED (EXCP, BTAM)
	. .1. . . . .		DCBMRWRT	"DCBBIT2"– WRITE (BSAM, BPAM, BISAM, BDAM, BTAM)
	. .1. . . . .		DCBMRRDQ	"DCBBIT2"– READ FOR LINE GROUP (QTAM) --- ALWAYS ZERO (QSAM, QISAM) --- RESERVED (EXCP)
	. . .1 . . . .		DCBMRMVP	"DCBBIT3"– MOVE MODE OF PUT (QSAM, QISAM)
	. . .1 . . . .		DCBMRWRK	"DCBBIT3"– KEY SEGMENT WITH WRITE (BDAM) --- ALWAYS ZERO (BISAM) --- RESERVED (EXCP, BSAM, BPAM, QTAM, BTAM)
	. . . . 1. . .		DCBMR5WD	"DCBBIT4"– FIVE-WORD DEVICE INTERFACE (EXCP)
	. . . . 1. . .		DCBMRLDM	"DCBBIT4"– LOAD MODE BSAM (CREATE BDAM DATA SET) (BSAM)
	. . . . 1. . .		DCBMRLCP	"DCBBIT4"– LOCATE MODE OF PUT (QSAM, QISAM)
	. . . . 1. . .		DCBMRIDW	"DCBBIT4"– ID ARGUMENT WITH WRITE (BDAM) --- ALWAYS ZERO (BISAM) --- RESERVED (BPAM, QTAM, BTAM)
	. . . . .1. .		DCBMR4WD	"DCBBIT5"– FOUR-WORD DEVICE INTERFACE (EXCP)
	. . . . .1. .		DCBMRPT2	"DCBBIT5"– POINT (WHICH IMPLIES NOTE) (BSAM, BPAM)
	. . . . .1. .		DCBMRTMD	"DCBBIT5"– SUBSTITUTE MODE (QSAM)
	. . . . .1. .		DCBMRUIP	"DCBBIT5"– UPDATE IN PLACE (PUTX) (QISAM) --- ALWAYS ZERO (BISAM) --- RESERVED (BDAM, QTAM, BTAM)
	. . . . . .1.		DCBMR3WD	"DCBBIT6"– THREE–WORD DEVICE INTERFACE (EXCP)
	. . . . . .1.		DCBMRCTL	"DCBBIT6"– CNTRL (BSAM, QSAM)
	. . . . . .1.		DCBMRSTK	"DCBBIT6"– SETL BY KEY (QISAM)
	. . . . . .1.		DCBMRAWR	"DCBBIT6"– ADD TYPE OF WRITE (BDAM) --- ALWAYS ZERO (BISAM) --- RESERVED (BPAM, QTAM, BTAM)
	. . . . . . .1		DCBMR1WD	"DCBBIT7"– ONE–WORD DEVICE INTERFACE (EXCP)
	. . . . . . .1		DCBMRSWA	"DCBBIT7"– USER'S PROGRAM HAS PROVIDED A SEGMENT WORK AREA POOL (BSAM CREATE BDAM, BDAM)
	. . . . . . .1		DCBMRDMD	"DCBBIT7"– DATA MODE (QSAM)
	. . . . . . .1		DCBMRSTI	"DCBBIT7"– SETL BY ID (QISAM) --- ALWAYS ZERO (BISAM) --- RESERVED (BPAM, QTAM, BTAM)
FOUNDATION AFTER OPEN
40 (28)	ADDRESS	2	DCBTIOT	OFFSET FROM TIOT ORIGIN TO TIOELNGH FIELD IN TIOT ENTRY FOR DD STATEMENT ASSOCIATED WITH THIS DCB
42 (2A)	BITSTRING	2	DCBMACRF (0)	– SAME AS DCBMACR BEFORE OPEN
42 (2A)	BITSTRING	1	DCBMACF1	– FIRST BYTE OF DCBMACRF
43 (2B)	BITSTRING	1	DCBMACF2	– SECOND BYTE OF DCBMACRF
44 (2C)	ADDRESS	4	DCBDEBAD (0)	– ADDRESS OF ASSOCIATED DEB
44 (2C)	BITSTRING	1	DCBIFLGS	– SAME AS DCBIFLG BEFORE OPEN
	11. . . . . .		DCBIFEC	"DCBBIT0+DCBBIT1"– CORRECTION INDICATOR
	. .11 . . . .		DCBIFPCT	"DCBBIT2+DCBBIT3"– PRINTER CARRIAGE TAPE PUNCH INDICATOR
	. . . . 11. .		DCBIFIOE	"DCBBIT4+DCBBIT5"– IOS ERROR ROUTINE USE INDICATOR
	. . . . . .1.		DCBIFLDT	"DCBBIT6"– POSSIBLE LOST DATA CONDITION SUCH AS FOR A PRINTER
45 (2D)	ADDRESS	3	DCBDEBA	– ADDRESS OF ASSOCIATED DEB
48 (30)	ADDRESS	4	DCBREAD (0)	– ADDRESS OF READ MODULE
48 (30)	ADDRESS	4	DCBWRITE (0)	– ADDRESS OF WRITE MODULE
48 (30)	BITSTRING	1	DCBOFLG	SAME AS DCBOFLGS BEFORE OPEN
49 (31)	ADDRESS	3	DCBREADA (0)	ADDRESS OF READ MODULE
49 (31)	ADDRESS	3	DCBWRITA	ADDRESS OF WRITE MODULE
48 (30)	ADDRESS	4	DCBGET (0)	– ADDRESS OF GET MODULE
48 (30)	ADDRESS	4	DCBPUT (0)	– ADDRESS OF PUT MODULE
48 (30)	BITSTRING	1	DCBOFLG1	SAME AS DCBOFLGS BEFORE OPEN
49 (31)	ADDRESS	3	DCBGETA (0)	ADDRESS OF GET MODULE
49 (31)	ADDRESS	3	DCBPUTA	ADDRESS OF PUT MODULE
QTAM INTERFACE
52 (34)	CHARACTER	4	DCBKSTAT (0)	– FOUR THRESHOLD VALUES FOR ERROR COUNTS
52 (34)	SIGNED	1	DCBKSTA1	–THRESHOLD VALUE FOR NUMBER OF TRANSMISSIONS
53 (35)	SIGNED	1	DCBKSTA2	– THRESHOLD VALUE FOR NUMBER OF DATA CHECKS
54 (36)	SIGNED	1	DCBKSTA3	– THRESHOLD VALUE FOR NUMBER OF INTERVENTIONS REQUIRED
55 (37)	SIGNED	1	DCBKSTA4	–OLD VALUE FOR NUMBER OF TIMEOUTS
QTAM POLLING LIST ORIGIN
56 (38)	ADDRESS	4	DCBCPOLL (0)	– A 4–BYTE FIELD FOR EACH POLLING LIST
56 (38)	BITSTRING	1	DCBPLBYT	–ADAPTER TYPE
1	. . . . 1. . .		DCBCPWTT	"DCBBIT4"– WTTA
57 (39)	ADDRESS	3	DCBCPOLA	– ADDRESS OF THE POLLING LIST
BTAM INTERFACE
52 (34)	ADDRESS	4	DCBLERB (0)	– ADDRESS OF LINE ERROR BLOCK
52 (34)	BITSTRING	1	DCBRDYI (0)	– READYQ INDICATORS
	. . . . .1. .		DCBRDYPO	"DCBBIT5"– APPLICATION REQUESTS NOTIFICATION OF POWER®–ON THAT IS AFTER INITIAL READY
	. . . . . .1.		DCBRDYIQ	"DCBBIT6"– ADDRESS IS READYQ AND NOT LERB
	. . . . . . .1		DCBRDYIZ	"DCBBIT7"– READYQ SPECIFIED, BUT ADDRESS WAS 0, SO USING BTAM READYQ ROUTINE
52 (34)	ADDRESS	4	DCBRDYQ	– ADDRESS OF USER/BTAM ROUTINE TO PROCESS LOCAL 3270 DEVICE READY INTERRUPTS
BSC INTERFACE
56 (38)	BITSTRING	1	DCBXMODE	– MODE OF TRANSMISSION FOR BINARY SYNCHRONOUS COMMUNICATION (BSC)
	.1. . . . . .		DCBXMIBC	"DCBBIT1"– INTERMEDIATE BLOCK CHECKING IS TO BE PERFORMED
	. .1. . . . .		DCBXMDA1	"DCBBIT2"– TRANSMISSION IS THROUGH A 2701 DATA ADAPTER UNIT DUAL COMMUNICATION INTERFACE B
	. . . . 1. . .		DCBXMDA2	"DCBBIT4"– TRANSMISSION IS IN CODE B FOR A 2701 DATA ADAPTER UNIT DUAL CODE FEATURE
57 (39)	BITSTRING	1	DCBXCODE	– BSC CONTROL STATION FLAG AND TRANSMISSION CODE
	1. . . . . . .		DCBXCCSF	"DCBBIT0"– BSC CONTROL STATION FLAG --- IF ZERO, THIS IS THE CONTROL STATION. IF ONE, THIS IS THE REMOTE STATION.
1	.1. . . . . .		DCBXCPTP	"DCBBIT1"– IF PTOP IS SPECIFIED IN SYSGEN PROCEDURE – SCHEDULE AN ASYNCHRONOUS EXIT TO INTERFACE RESOLUTION ROUTINE
	. .1. . . . .		DCBXCTR1	"DCBBIT2"– 6–BIT TRANSCODE IS BEING USED (BIT 4 IS ALSO ON)
	. . .1 . . . .		DCBXCAS1	"DCBBIT3"– USASCII TRANSMISSION CODE IS BEING USED (BIT 5 IS ALSO ON)
	. . . . 11. .		DCBXCEBC	"DCBBIT4+DCBBIT5"– IF BOTH BITS ARE ZERO, EBCDIC TRANSMISSION CODE IS BEING USED.
	. . . . 1. . .		DCBXCTR2	"DCBBIT4"– 6–BIT TRANSCODE IS BEING USED (BIT 2 IS ALSO ON)
	. . . . .1. .		DCBXCAS2	"DCBBIT5"– USASCII TRANSMISSION CODE IS BEING USED (BIT 3 IS ALSO ON)
58 (3A)	CHARACTER	1	DCBBSRSV	– DLE CONTROL CHARACTER
59 (3B)	BITSTRING	1	DCBBSWBT	– RESERVED
60 (3C)	ADDRESS	4	DCBIRRAD (0)	– BEFORE OPEN – IF PTOP IS SPECIFIED IN THE SYSGEN PROCEDURE, ADDRESS OF INTERFACE RESOLUTION ROUTINE. AFTER OPEN, THE FOLLOWING 4 CHARACTERS OCCUPY THIS SPACE.
60 (3C)	CHARACTER	1	DCBBSTSX	– DLE CONTROL CHARACTER
61 (3D)	CHARACTER	1	DCBBSSTX	– STX CONTROL CHARACTER
62 (3E)	CHARACTER	1	DCBBSTEX	– DLE CONTROL CHARACTER
63 (3F)	CHARACTER	1	DCBBSETX	– ETX CONTROL CHARACTER
64 (40)	CHARACTER	2	DCBBSAK0	– ACK–0 CONTROL CHARACTER
66 (42)	CHARACTER	2	DCBBSAK1	– ACK–1 CONTROL CHARACTER
68 (44)	CHARACTER	1	DCBBSENQ	– ENQ CONTROL CHARACTER
69 (45)	CHARACTER	1	DCBBSNAK	– NAK CONTROL CHARACTER
70 (46)	CHARACTER	1	DCBBSETB	– ETB CONTROL CHARACTER
71 (47)	CHARACTER	1	DCBBSDLE	– DLE CONTROL CHARACTER
72 (48)	CHARACTER	1	DCBBSEOT	–NTROL CHARACTER
73 (49)	CHARACTER	3	DCBBSSYN	– SYN, SYN, SYN CONTROL CHARACTERS
76 (4C)	CHARACTER	2	DCBBSONL	–SOH % CONTROL CHARACTERS
78 (4E)	CHARACTER	2	DCBBSSAK	– WACK CONTROL CHARACTERS
80 (50)	CHARACTER	2	DCBBSRVI	– DLE @ CONTROL CHARACTERS
82 (52)	BITSTRING	18		– RESERVED