Primer – IBM i – AS400/iSeries Modernization 

 April 13, 2021

By  NickLitten

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programmer modernization project war room

From AS400/RPG to IBMi/RPGLE

I’ve been involved in some interesting software modernization projects recently. Ranging from application replacements to middleware web service integrations to light code dusting. The main thing I’ve learned is

  • archaic program source code can be a very delicate beast like a stack of cards ready to fall at the slightest push
  • prehistoric programmers seemed to enjoy doing things the hard way
  • good programmers write commented code
  • bad programmers don’t add comments, use obscure over-complicated techniques and purposefully obfuscate business logic behind complex procedures to make themselves feel clever
  • decades ago we (programmers) were part of a competition to see who could write the longest programs
  • modern modular programming techniques are not only easier to follow, easier to debug but smarter, faster and just plain sexier
  • Modern RPG ILE language has a beautiful flow to it that RPG 2/3 (even using the ubiquitous Logic Cycle) cannot match
  • I love *LOVE* playing with old code and breathing new life into it 🙂

I really love taking old RPG code, giving it a good spring clean, and releasing a fresh sleeker faster version of decades-old code. Forget Alcoholics Anonymous, I should attend a software modernization addicts meetings where AA = AS400 Anonymous

“Yes my name is Nick Litten and I am a RPG modernization-a-holic”

Me – in my last AA meeting

A frequently asked question in project kick off meetings is “What is AS400 modernization?”. So lets look have a quick high level chat about what it is, what we should think about and how we get it moving…

How do we start our modernization project?

The driving idea behind modernizing a legacy IBM AS400 application is much more than the simple task of refactoring our old RPG and CLP codebase.

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IBM i Software Developer, Digital Dad, AS400 Anarchist, RPG Modernizer, Shameless Trekkie, Belligerent Nerd, Englishman Abroad and Passionate Eater of Cheese and Biscuits. Nick Litten Dot Com is a mixture of blog posts that can be sometimes serious, frequently playful and probably down-right pointless all in the space of a day. Enjoy your stay, feel free to comment and remember: If at first you don't succeed then skydiving probably isn't a hobby you should look into.

Nick Litten

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