System Control Blocks

Offset
16 (10) 1
17 (11) • 1
18 (12) •• 1
Bytes and Field
Alignment Name
19 (13) • 1
20 (14) 1
21 (15) • 3
24 (18) 1
25 (19) • 1
26 (lA)
26 (lA)
27 (lB)
28 (lC) 1
29 (lD) • 3
32 (20) 1
33 (21) • 3
36 (24) 1
37 (25) • 3
2
DCBBQFLG
x •••• xxx
. 1 ••
• .1.
• •• 1 1 •••
DC BWTEOM
DCBWTEOT
DCBWTPAD
DCBBUFRQ
DCBCLPS
DCBINTVL
DCBDSORG
Byte 1
xx •• xxxx
• .01
Byte 2
DCBDEVTP
DCBIOBAD
DCBCPRI
xxxx x •••
• 1 •.
. . 1.
. . . 1
DCBLCBAD
DC BE IOBX
DCBEXLST
DATA CONTROL BLOCK -- QTAM
Field Description, Contents, Meaning
>
WTTA INTERFACE
WTTA flag byte.
(Res erved hits)
WRU feature is to be used •
lAM feature is to be used.
WRU feature to be used in the send header subgroup.
WRU feature is to be used in the end send subgroup.
The EOM character.
The EOT character.
Number of padding characters required for motor-on
delay.
LINE GROUP INTERFACE
Number of buffers requested for a read or write
operation.
Address of the line procedure specification routine.
Number of seconds of intentional delay between passes
through a polling list for nonswitched lines.
Reserved.
Data set organization.
(Reserved bits)
ex Line group.
Reserved.
86 OS System Control Blocks (Release 21.7)
Device type pointer.
Address of first lOB.
Communication priority. Relative priority to be
given to sending and receiving operations.
R
E
S
(Reserved bits)
Receiving has priority •
Receiving and sending have equal priority •
Sending has priority •
Base for addressing LCBs.
(Base = Address of first LCB minus length of one
LCB).
Extended lOB index. Size of a line control block
(LCB).
Address of the exit list.