MIDRANGE COMPUTING

REPRINT    -     NOVEMBER 1996

This material has been reprinted with permission from the November 1996 issue of Midrange Computing.

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TARGET/400
Convert S/36 applications to native mode on the AS/400.

by JANET M. FRASER

wpe161.jpg (1084 bytes)omewhere around the age of one, you took your first steps.  Perseverance and practice led to a balanced, easy stride.   Later, when you learned to run, you enhanced the movement.  Writing application software is a bit like learning to walk.  At first, you squeal with delight when your program compiles.  Soon, you are determined to make it work dependably.  Then you add bells and whistles!  But before you know it, technology changes, and your application is left wearing armor-clad boots instead of gel-filled athletic shoes. What to do?

   Convert. Not in the religious sense, but in the technological sense. Automated conversion of applications can result in cost-effective, native- mode AS/400 applications from what were once S/36 programs. Further- more, these converted applications can be brought into production at less cost and in less time than a manual redevelopment project or an application rewrite if you use the right tool.

   TARGET/400 is a conversion tool that enables the S/36 user to convert S/36 applications to native mode on the AS/400. The applications may be converted directly from the S/36 or, alternatively, from the S/36 environment on the AS/400. Conversion capabilities exist for RPG II to RPG III and OCL to CL.   TARGET/400 can convert menus, screen formats, message members, sorts, queries, data dictionaries, and files (DDS generation).

A Good Relationship

   Native mode RPG III applications on the AS/400 give you the advantage of maintaining your programs in a relational database environment, so record descriptions are external to the applications and need not be coded in the RPG programs that use them. Not only does this reduce the coding requirements during program development, but also it ensures record-format integrity.

   TARGET/400 emphasizes the creation of a well-structured and defined relational database environment.  The software generates comprehensive, consistent, and detailed DDS specifications for converted database files. These definitions form the foundation for any future developments or enhancements to your converted applications.  The definitions also allow you to take advantage of the advanced database file functions available to the AS/400 native mode user.   TARGET/400 offers the ability to automatically optimize your converted applications for performance, which can improve application response times as well.

   If conversion is accomplished directly from the S/36, you need only save the libraries and files you wish to convert from the S/36 using the SAVELIBR and SAVE commands.  The saved media then is used as input to the conversion aid.

Working Together

   OCL procedures are converted to CL programs; typically in excess of 98 percent of the OCL is converted.  Sort parameters are extracted from OCL and converted to native mode sort source members for use by the native Format Data (FMTDTA) command in the converted CL programs.  TARGET/400 supplies the Sort Data (SRTDTA) command , which permits the use of parameter and substitution expressions in the native mode sort statements.

   S/36 screen format specifications are converted to DDS specifications.

   Field reference file processing automatically updates any application field reference file with the field specifications of any file description processed by the DDS generator.  An interactive logical file creation feature allows you to quickly and easily build any logical files (alternate indexes) and associated DDS.

   TARGET/400's interactive learning module enables the user to create detailed CL programs.  The software accomplishes this by using familiar S/36 OCL statements.

   Two post-conversion features of TARGET/400 should also be highlighted.  First, the RPG file description externalization feature enables you to optionally replace internal RPG III file, screen, and printer descriptions with their corresponding external definitions.  This process implements field name standardization throughout the converted RPG III code.  Second, TARGET/400's change analysis functions permits you to plan ahead by providing impact-analysis reporting to help you effectively manage any changes to your native mode applications.

   Like a new pair of athletic shoes, TARGET/400 should put some spring back in your step while helping you to trim seconds off your time.


Janet M. Fraser is the products editor for Midrange Computing

She can be reached by E-Mail at: fraser@midrangecomputing.com