System Control Blocks

Offset
101 (65) • 1
101 (65) • 1
101 (65) • 1
102 (66) •• 2
102 (66) •• 2
104 (68) 2
106 (6A) •• 1
Bytes and Field
Alignment Name
107 (6B) ••• 1
106 (6A) •• 1
107 (6B) ••• 1
1 ••.
• x.. . x ••
•• 1.
.•. 1
1 ...
. 1 •.
· .1.
• .• 1
1 •••
· .1.
• •• 1
1 .•.
• xx.
• .. 1
•• 1.
•• 1.
• •• 1
xx.x xx ••
JFCBLKSI
JFCBUFSI
JFCLRECL
JFCNCP
JFCNTM
JFCBUFMX
JFCPCI
1 •••
.1 •.
•• 1.
.•• 1
1 ••.
.1 ••
· .1.
••• 1
JOB FILE CONTROL BLOCK
Field Description, Contents, Meaning
BISAM, QISAM
Code
W Write validity check.
(Reserved bits)
M Master Indexes •
I Independent overflow area •
Y Cylinder overflow area.
L Delete option.
R Reorganization criteria.
BDAM
W Write validity check.
Track overflow •
E Extended search.
F Feedback.
A Actual addressing.
(Reserved bits)
R Relative block addressing.
TeAM
Code
C
L
R
Checkpoint data set •
Non-reusable message queue data set •
Reusatle message queue data set.
(Reserved bits)
Maximum block size.
TeAM: The size of all buffers used for this line
group.
Logical record length.
Number of channel programs; number of READ or WRITE
requests which may be issued prior to a CHECK; number
of lOBs generated. Maximum value: 99.
NOTE: This field is not used by GAM. GAM uses the
field JFCBFTEK for this information.
The number of tracks that determine the development
of a master index. Maximum value: 99.
TCAM segment
The maximum number of buffers to be us-ed for data
transfer for each line in this line group.
Program-controlled interruption handling.
Code PCI=
(X, )
(, X)
(A, )
( ,A)
(N, )
(, N)
(R, )
( ,R)
232 os System Control Blocks (Release 21.7)