IBM OS/390 User Manual
VSE 2.1 for the EXEC statement), or change the program
′
s logic to read and
process a
″
control record
″
which would supply any variable information to
the program.
Additional programming changes and considerations can be found in their
respective programming chapters and in the POWER-JES2 differences chapter.
The Cortex Migration System can provide conversion assistance in many of the
areas where VSE-OS/390 incompatibilities exist.
respective programming chapters and in the POWER-JES2 differences chapter.
The Cortex Migration System can provide conversion assistance in many of the
areas where VSE-OS/390 incompatibilities exist.
32.5.1.2 Common VSE Coding Practices Causing Conversion
Problems
Problems
The following are some common VSE program coding
″
practices
″
that won
′
t
work in OS/390, and since they are mostly logic errors, won
′
t be
″
picked-up
″
nor
notated by a conversion tool.
•
In COBOL, referencing a file
′
s (or printer
′
s) I/O area before the file (or
printer) is OPENed. This will result in a system 0C4 abend in OS/390.
•
In COBOL, referencing a file
′
s (or printer
′
s) I/O area after the file (or printer)
is CLOSEd. This will result in a system 0C4 abend in OS/390.
•
In COBOL,
″
STOP RUN
″
statements should not be embedded within SORT
procedures. These should be removed from all SORT procedures; that is,
sorts must end before a STOP RUN can be requested.
sorts must end before a STOP RUN can be requested.
•
Not OPENing a unit record file will work in VSE, but abend in OS/390.
•
In Assembler, using other than registers 2 through 12 for application
purposes. (Registers 0, 1, 13, 14, and 15 are used for special purposes by
OS/390.)
purposes. (Registers 0, 1, 13, 14, and 15 are used for special purposes by
OS/390.)
32.5.2 JCL Conversion
Mass conversions use the following steps for JCL conversion.
•
Conversion
The file information extracted during program conversion and associated
data such as VSE disk and tape catalog data, is used by the conversion tool
to generate individual job stream flow charts. This is done on a job by job
basis.
data such as VSE disk and tape catalog data, is used by the conversion tool
to generate individual job stream flow charts. This is done on a job by job
basis.
•
Integration
The job stream flow charts are consolidated enterprise-wide to separate the
application data flows (several independent data flows may use the same
VSE label and even the same VSE disk space, but they become separate
data sets in OS/390).
application data flows (several independent data flows may use the same
VSE label and even the same VSE disk space, but they become separate
data sets in OS/390).
In the Cortex tool a function called file integration automates the
classification of files and jobs. It also prepares reports that help determine if
a file requires manual intervention. The information needing to be
understood for these files and jobs includes:
classification of files and jobs. It also prepares reports that help determine if
a file requires manual intervention. The information needing to be
understood for these files and jobs includes:
−
Where does the file or job reside?
−
Is it permanent or temporary?
−
Where does it come from?
−
Where does it go to?
•
File classification
Based on data flow patterns and other functional attributes (organization,
record length, and so on) files are classified according to their life cycle:
record length, and so on) files are classified according to their life cycle:
504
VSE to OS/390 Migration Workbook