IBM System/360 System Programmer's Guide

r----------------------------------------------------------------------,
Work Area
(100 bytes)
Job File Control Block (JFCB)
(176 bytes)
Event Control Block
(ECB) - 4 bytes
Input Output Block (lOB)
(40
bytes)
Data Extent Block
(DEB)
(44 bytes)
Abbreviated DCB - (4 bytes)
Channel Command Words (CCW)
(96 bytes)
~----------------------------------------------------------------------~
I Each of the fields within the work and control block area can be I
I
addressed by your nonstandard label processing routines. The I
I
IECDSECT macro-instruction defines the symbolic names of all these I
I fields. (The macro-definition and how to add it to the macro- I
I library are in the Appendix of this chapter.) Code this macro- I
I
instruction (with a null operand field and immediately preceded by a I
I
DSECT statement) in the list of constants for each of your I
I
nonstandard label processing routines. Using the starting address I
I
of the work area as a base, you are able to address any field I
I
symbolically. I
L ______________________________________________________________________ J
Figure 2. Format of Combined Work and Control Block Area
48

IBM System/360 Specifications

General

Brand	IBM
Model	System/360
Category	Desktop
Language	English