System Control Blocks

Offset
+1
Bytes and Field
Alignment Name
• 3
EVENT CONTROL BLOCK
Hex.
Dig. Field Description, Contents, Meaning
Access Methods Except BTAM and TCAM (Continued)
4F Error recovery routines have been entered because of
direct access error but are unable to read home
address or record o. (CSW contents do not apply.)
50 Channel program terminated with error.
was a DOS embedded checkpoint record.
do not apply.)
BTAM
Input block
(CSW contents
7F Completed normally.
41 Completed with an I/O error.
48 Enable command halted, or, I/O operation purged.
7F Normal completion (work unit in work area).
70 The SETEOF macro was issued in the message command
program (no work unit in work area).
50 Message was not found when the READ macro was issued
in conjunction with the POINT macro to retrieve a
message.
5C Congested destination message queue data set (write
only).
58 Sequence error.
54 Invalid message destination.
52 Workarea overflow.
204 OS System Control Blocks (Release 21.7)
02 End-of-queue condition (not end-of-file).
01 Read-ahead queue empty, but destination queue not
empty.
40 Data is on read-ahead queue.
Awaiting completion of an event:
Request block address.
After completion of the event:
Zeroes, or remainder of completion code.