System Control Blocks

Offset
72 (48) 4
76 (4C) 2
78 (4E) •• 2
80 (50) 1
81 (51) • 1
82 (52) 2
84 (54) 1
85 (55) • 3
88 (58) 8
96 (60) n
Bytes and Field
Alignment Name
4
2
• • 2
2
• • 1
• • • 1
1
• 1
• • 2
LCBRESTR,
IOBRESTR
LCBINCAM,
IOBINCAM
Byte 1
Byte 2
LCBERRCT,
IOBERRCT
LCBUCBX
LCBTEMP
LCBTRST
LCBPOLCT
LCBPOLPT
LCBERCCW
LCBCPA
LERACTR
LERACDC
LERACIR
LERACTO
LERTHTR
LERTHDC
LERTHIR
LERTHTO
LINE CONTROL BLOCK
Hex.
Dig. Field Description, Contents, Meaning
01
02
04
08
10
40
00
Address of the CCW for 510 command for first message
data trans fer.
Line trying to send.
Dial line not available.
Polling or addressing error.
WTTA:
Halt I/O instruction has been used.
EOT character received.
WRU character received.
Always zero.
Counter for BREAKOFF routine.
END OF INPUT/OUTPUT BLOCK FORMAT
Index to the address of the UCB in the DEB.
Temporary storage for message priority.
Address of end-of-block (EOB) character relative to
the address of the last correctly transmitted segment
of current message.
Count of messages received from terminal.
Pointer to currently active entry in polling list.
Work area to hold CCW built by error recovery
procedures.
Channel program area.
LINE ERROR BLOCK (LERB)
A field in the LERB is found by adding the value in
the DCBEIOBX field in the DCB to the address of the
LCB and subtracting the field reversal value.
Cumulative counters for number of:
Transmissions.
Da ta checks.
Interventions required.
Timeouts.
Threshold counters for Number of:
transmissions.
Data checks.
Interventions required.
Timeouts.
Reserved.
246 OS System Control Blocks (Release 21.7)
END OF LINE CONTROL BLOCK