System Control Blocks

Offset
Bytes and Field
Alignment Name
36 (24) 4 DECPOLPT
40 (28) 2
42 (2A) •• 2 DECWLNG
44 (2C) 4 DECWAREA
DATA EVENT CONTROL BLOCK -- BTAM
Hex.
Dig. Field Description, Contents, Meaning
One of these:
Programmed Polling:
Address of the current entry in the polling list.
Autopoll:
Byte 1: Index to current entry in polling list.
Bytes 2-4: Address of polling list.
BSC On-Line test:
Address of text data.
BSC Extension
Fields are present only if a slwlist is coded for the
area and length operands of the READ or WRITE macro
instruction that defines the DECB.
Reserved.
160 OS System Control Blocks (Release 21.7)
Length, in bytes, of the data area in
leading-graphics and conversational type operations,
or of the area containiRg the tone characters in read
connect with tone (TCW) operations.
Address of the data area in leading-graphics and
conversational operations, or of the area containing
the tone characters, in read TCW operations.