Differences Between OPM RPG/400 and ILE RPG

Appendix

A.

Behavioral

Differences

Between OPM

RPG/400

 

 

 

 

 

and ILE

RPG

for

AS/400

 

 

 

 

 

 

 

 

 

 

 

The

following

lists

note differences

in the

behavior of

the OPM

RPG/4

 

 

and

ILE

RPG.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Compiling

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

1. If

you

specify CVTOPT(*NONE)

in OPM

RPG,

all

externally

described f

 

 

 

that

are

of a type or with attributes not supported by RPG wi

 

 

 

specify

CVTOPT(*NONE) in ILE RPG, all

externally

described fields

will

 

 

 

brought into the program with the same type as specified in the

 

 

 

description.

 

 

 

 

 

 

 

 

2.In RPG IV there is no dependency between DATEDIT and DECEDIT in control specification.

 

3. Regarding

the

ILE RPG create commands (CRTBNDRPG

and CRTRPGMOD):

 

¹ The IGNDECERR parameter on the CRTRPGPGM command has been

 

replaced by the FIXNBR parameter on the ILE RPG

create

comm

IGNDECDTA ignores any decimal data errors

and

continues with

the

machine instruction. In some cases, this

can

cause

fields

to

with incorrect and sometimes unpredictable

values.

FIXNBR corre

data in

a

predictable manner before it

is

used.

 

¹There is a new parameter, TRUNCNBR, for controlling whether numer

 

 

overflow

is

allowed.

 

 

 

 

 

 

 

 

 

¹

There are

no

auto

report

features or commands in RPG IV.

 

¹

You

cannot

request

an

MI

listing from

the compiler.

 

4. In a

compiler

listing,

line

numbers start at 1 and increment by

source

or

generated

specifications,

when

the default

OPTION(*NOSRCST

is specified. If OPTION(*SRCSTMT) is specified, sequence numbers a

instead of line numbers. Source IDs

are

numeric,

that

is, there

AA000100

line

numbers for

 

/COPY

members

or

expanded

DDS.

 

5.RPG IV requires that all compiler directivesbeforecompileappear-time data, including /TITLE. When RPG IV encounters a /TITLE directive, it will data. (RPG III treats /TITLE specifications as compiler directiv the source.)

 

The Conversion Aid will remove any /TITLE

specifications

it

encounters

 

compile-time

data.

 

 

 

 

 

 

 

 

 

 

 

 

 

6.

ILE

RPG

is

more

rigorous in

detecting

field

 

overlap

in

data

struc

 

some calculation operations involving overlapping operands, ILE RPG

issu

 

message

while

the

OPM

compiler

does

not.

 

 

 

 

 

 

7.

In ILE RPG the word NOT cannot

be

used as

a

variable

name.

NOT

 

special

word

that

is

used

as

an

operator

in

 

expressions.

 

8.

At

compile

time,

the

source

is

read

using

the

CCSID

of

the

main

 

while for

OPM

RPG,

the source

is read using

the CCSID

of the jo

Copyright IBM Corp. 1994, 1999

373

Page 396 Page 398
Page 397
Image 397
IBM manual RPG/400 ILE, For AS/400, Appendix, Differences, Between OPM
Page 396 Page 398

AS/400 specifications

The IBM AS/400, now known as the IBM iSeries, is a midrange computer system that has been a cornerstone of enterprise computing since its introduction in 1988. Designed to provide a robust platform for business applications, the AS/400 is celebrated for its reliability, scalability, and integrated database capabilities.

One of the key features of the AS/400 is its Integrated Operating Environment, which blends hardware and software resources seamlessly. This integration allows businesses to execute diverse workloads, ranging from traditional applications to modern web-based services, all on a single platform. The operating system, OS/400 (now IBM i), offers a rich set of APIs and tools for developers, simplifying application development and management.

Another standout characteristic of the AS/400 is its built-in database, DB2 for i. This powerful relational database management system allows for efficient data handling and provides advanced features such as support for SQL, XML, and JSON, making it easier for businesses to manage their data and integrate it with other systems. The database's tight integration with the operating system enables high performance and security.

In terms of scalability, the AS/400 can accommodate small businesses as well as large enterprises, with the ability to support hundreds of users simultaneously. Its architecture allows for easy upgrades in hardware, meaning that organizations can scale their systems without replacing the entire infrastructure.

Security is another critical attribute of the AS/400. With a sophisticated security model, it offers built-in user authentication, access control, encryption, and auditing capabilities to protect data and applications from unauthorized access.

The AS/400 also supports multiple programming languages, including RPG, COBOL, Java, and PHP, giving organizations the flexibility to choose the development tools that best fit their needs. This diversity helps maintain legacy applications while also developing new ones that leverage modern technologies.

Moreover, the platform supports both traditional green-screen interfaces and modern graphical user interfaces, allowing organizations to transition smoothly into contemporary user experience paradigms.

Overall, the IBM AS/400 stands out as a resilient, flexible, and secure computing platform that enables organizations to effectively manage their business operations, streamline processes, and adapt to changing market demands. Its unique combination of integrated features and capabilities ensures that it remains relevant in today's fast-paced technology landscape.
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