System Control Blocks

Offset
68 (44) 1
70 (46) •• 2
72 (48) 8
72 (48)
77 (4D)
78 (4E)
JOB FILE CONTROL BLOCK
Bytes and
Alignment
Field
Name Field Description, Contents, Meaning
JFCFUNC
1 ...
• 1 ••
•• 1.
• •• 1
FUnction indicators for the 3505 Card Reader/3525
Card Punch specified by the FUNC parameter.
I - Interpret (punch and print two lines)
R - Read •
P - Punch.
W - Print.
1::: D - Data protection:
.1.. X - Data set is to be printed. This may be coded
with PW or RPW to distinguish the data set to be
printed from the data set to be punched •
•• 1. T - Two line print support request. The second print
line is located on card line three.
JFCBVLSQ
JFCBMASK
Bytes 1-5
Byte 6
1 •••
• 1 •.
. " .1.
.•. 1
Byte 7
1 ..•
• 1 ••
· .1.
xxxx
• •• 1 ••••
1 ..•
.1 ..
.. 1.
· . .. . .. 1
Volume sequence number.
Data management mask.
OPEN routine internal switches.
Volume label processing required.
creation of a standard label is necessary •
Destruction of a standard label is necessary •
Dual-density check detected •
OPEN routine internal switches.
Treat the INOUT option of OPEN as INPUT.
Treat the OUTIN option of OPEN as OUTPUT •
Checkpoint/restart: Set only in a JFCB recorded in a
data set descriptor record (DSDR) by the checkpoint,
routine. Indicates that the data set related to the
JFCB is being processed sequentially, at the
checkpoint, on a volume other than the volume on
which processing began in the current step. When
restart occurs, the bit causes deferred volume
mounting. (NOTE: Checkpoint/restart does not
rewrite the JFCB to SYS1.JOBQ, therefore this bit
usage is internal to the component.)
OPEN: Set to indicate that this data set resides on
a non-RPS device. The bit is interfaced by OPEN
executors when building channel programs and
selecting processing routines. (NOTE: This bit is
turned off by OPEN before the JFCB is rewritten to
SYS1.JOBQ, therefore this bit usage is internal to
OPEN. )
Disposition of this data set has been changed from
MOD to NEW. Disposition (in JFCBIND2) will be
restored to MOD after OPEN.
Search direct for rotational position sensing (RPS)
devices.
JFCTRACE - GTF trace is to occur during
OPEN/CLOSE/EOV.
Before OPEN: JFCBUFOF (offset 67) contains a buffer
offset or invalid information resulting from a
JFCB-to-JFCB merge.
After OPEN: OPEN may have stored a TTR in JFCBOTTR
(offset 67), in which case OPEN will have set this
bit to zero.
OPEN has updated the TTR. Scheduler will update the
TTR in the catalog if this data set is cataloged.
JFCB 227