Modernizing AS400 Green Screens


Jun 27

Modernizing AS400 aka WEB-ENABLING AS400 and iSeries

Converting an old green screen application to run in a website is as easy as typing an email or uploading a photo to facebook. If you are a modern IBM i Software developer the chances are, your system has lots of old AS400 and iSeries that code that is just begging to be modernized and given a web2.0 facelift!

The good news is that there are plenty of tools out there to make this process deadly easy. Mostly the only change to the RPG code is addition of a single line below the WORKSTN definition in the ‘F’ Specs: using the HANDLER keyword. This basically tells the IBM i operating system that we are expanding the interface for the DSPF to allow conversation with a web browser. Modernizing applications really is easy!

Here is an example of an old fashioned green screen that I have just modernized (the jury is still out regarding the use of the word “modernize”) using one of the “AS/400 modernization” companies tools. There are lots of companies in this space, but for this blog I will use the Profound Logic Screen Designer:

(1) Green Screen AS400 Application

Here is the old 1980’s style green screen… amazingly still used in this exact style throughout the business world today. It’s like the users have been frozen in time for the last twenty years, while their IT Department failed to notice this modern invention *cough* called the internet. I frequently hear the same message from the green-screen programmers “if its not broke — don’t fix it”.

AS400 Green screen using 5250 telnet emulation

Using green screen applications users are tied to using the keyboard, without point and click functions. It’s fast and basic, but also visually overwhelming and ignore all the UI & UX advances we now take for granted.

(2) Automatically converted green screen to webpage

Running the DSPF Source code though the automatic converter – modernizes this green screen and lets us use it in a web browser: any web browser. Obvious benefit #1 is removing the need to install 5250 emulation software or IBM Client Access… any operating system (Microsoft, Apple, Linux) can signon using the users browser of choice. Here is the same screen using Firefox:

simple modernized as400 application

(3) Design the screen adding some typical HTML functions

So, now I have just opened this screen in the designer and moved the layout around, added some nice colors to boxes to separate content and added a google-map widget to show the address in a more friendly way.

modernized as400 application running in a web browser

End result is an old green-screen application magically transformed into vibrant web 2.0 displays via any web browser. All the keyboard shortcuts, function keys and screen data remain fully functional – but now the user also has total point click, copy paste, web browser advantages. It’s magic.

Total editing time from start to finish?

Ten minutes.

If you are an IBM RPG Programmer… writing or maintaining green screen application ask yourself “Do my end users deserve a better interface?” I think the answer is obvious, don’t you?


About the Author

IBM i Software Developer, Digital Dad, AS400 Anarchist, RPG Modernizer, Alpha Nerd 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 in the words of the most interesting man in the world: Stay thirsty my friend.