Remote Job Entry Subsystems; Storage Required For Object Programs; Storage Required On Diskette; Main Storage Required For Execution - IBM 5280 Programmer's Manual

• From the host to a tape, and then through a data converter (for example,
the IBM 3747 Data Converter) to a diskette. The load modules on the
diskette could either be hand-carried to the 5280 system or sent over a
telecommunication link.
LTNotel: Ensure that the transparent text mode is specified on both the host
and the 5280 when sending object modules over a telecommunications link.
LTNote 2: 5280 RJE provides a name for the data set to which the object module
is sent. Therefore, you may want to change the name of the data set using the
facilities of the 5280 diskette label maintenance (SYSLABEL) utility. You
must change the name when the object modules are segmented. See the
section "When Programs Are Segmented" later in this chapter.
Information on the 5280 communications facilities, including RJE, is
described in the 5280 Communications Reference Manual.
Remote Job Entry Subsystems
If you use a remote job entry subsystem to transfer load modules from the host
to your 5280 system, you may have to use the DECK/NODECK option to
ensure that the size of the object records conforms with the size required by
your subsystem. Some remote job entry subsystems, such as RES, JES2,
DOS/VSE POWER, etc., require that the data to be transferred be made up
of 80-byte records.
Unless you specify otherwise, the compiler puts out load modules made up of
128-byte records. With the DECK/NODECK option, described in Chapter
7, you can cause the compiler to create load modules with 80-byte records.
Use this option if you require 80-byte records for your host subsystem or for
any other reason.
Storage Required for Object Programs
The information in this section will help you estimate (1) the storage required
for your COBOL object module on the diskette device and (2) the storage
required during execution in the partition. These requirements differ, as will
be shown.
Storage Required on Diskette
The number of bytes of diskette space needed by your COBOL program is
printed on the last page of the compiler listing. Either the OBJECT or LIST
option must be in effect during compilation. (These options are described in
Chapter 7. Unless you specify otherwise, the OBJECT option by default will
always be in effect.)
Main Storage Required for Execution
The main storage required by your program during execution will be at least
the amount printed on the compiler listing. In addition, you must add space
for I/O buffers, which are allocated dynamically during execution.
The amount of storage required for I/O buffers varies with the number of files
concurrently opened by your program and the sizes of the records in each file.
In allocating I/O buffers for your program, COBOL considers these variables
and the optimum performance that can be achieved. Because the variables
can differ greatly among users, no simple formula exists for determining the
I/O buffer size.
Chapter 8. Guide for COBOL Program Execution 8- 3