Whether you are designing software or purchasing it, one key consideration is the software’s user interface. Although the term user interface is often used to describe how software looks on the screen, that’s only one aspect of it. It also involves the way that users interact with the system.

If you’re developing or buying software, how do you decide which interface to use? The choices for user interfaces for AS/400 applications are numerous: 5250, HTML (the Web), Windows, Java GUIs, Notes/Domino, and others. If you’re a developer, the target platform you choose has enormous implications. Think of the developers who chose OS/2. If you’re a purchaser, the decision may not impact your entire business, but it does determine a huge portion of the cost of an application.

5250 is the original and most widely supported user interface for AS/400 applications. In its heyday, 5250 was ahead of its time. It’s still my favorite for keyboard- oriented applications, which are the mainstay of many businesses. Although 5250 is a main reason why the AS/400 has had a hard time being perceived as a modern server, it’s still the best for heads-down, transaction-based computing because it doesn’t require you to take your hands off the keyboard. The main problem for the “uninitiated” is that it isn’t graphical, which means it doesn’t lend itself well to visual, exploratory applications and doesn’t seem as “fun.” Another drawback is that, if you choose 5250, your target audience is limited to those with 5250 terminals or terminal emulators, and those are not universal.

Windows is another application target platform. Perhaps due to the early PC keyboard limitations, Windows apps aren’t as easily controllable on the keyboard as 5250 apps are, which means they are more difficult to make as productive for transaction- oriented systems. When you target the Windows platform, you get the advantages of a huge audience, GUI capabilities, good software tools, and the ability to interact closely with the client machine. The problems you are likely to encounter come later. For example, technical support of Windows-based software can be a nightmare. Dynamic Link Library (DLL) conflicts, weird third-party software, and strange hardware are things you may find yourself answering phone calls about. Of course, with effort, Windows can be made to run well enough, but it is more vulnerable to these problems than some of the other target platforms.

Another target platform is the Web and its derivatives. I’m referring to making the browser the target user interface for software, whether or not your applications are on the Internet. When you target the browser, your app can run on a myriad of clients, now and

into the future. Everyone knows how to use the Web, so training is minimal. Browsers are free and are everywhere, so deployment isn’t a big issue. Web interfaces can use rich text, graphics, sound, animation, and other media to interact with the user, and the AS/400 can serve them all. If you develop an application for internal use and later want to share portions of that application with the world, it is much easier to do than with the Web. Big investments have been made in the Web, so it’s likely to be around for a long time. There are many AS/400 tools that can be used to create a Web-based application, including RPG, Java, Domino, and Net.Data.

So why not just target only the Web? Of course the answer to that question is that you should use the appropriate tool for the job. If your application is oriented toward organizing and presenting information to users, the Web may be the only interface you need. However, it doesn’t offer the level of keyboard or mouse control that is required for rapid data input. Web applications are also terrible at printing from the browser, although that is remedied by printing from the server. Web apps also don’t have some of the interesting user interface tools and components that you’re used to seeing in other environments, although they are evolving quickly.

As you can see, there are a lot of implications when you choose a user interface. At Midrange Computing, we’re constantly revising our user interface. This month, we’ve changed the cover to make it easier to see what’s in the magazine. And we’ve brought back an enhanced version of Significa. It’s the place to turn to for industry news items, facts, figures, and product news and information. Designed to be a fast read, it will keep you up to speed on what’s going on in the AS/400 and midrange marketplace. Our goal is to help you stay smart and save time. Let us know how we’re doing at This email address is being protected from spambots. You need JavaScript enabled to view it..

Brian Singleton is former editor of Midrange Computing. He has worked in the IBM midrange arena for many years, performing every job from backup operator to programmer to systems analyst to technology analyst for major corporations and IBM Business Partners. He also has an extensive background in the PC world. Brian also developed a line of bestselling Midrange Computing training videos, authored the bestselling i5/OS and Microsoft Office Integration Handbook, and has spoken at many popular seminars and conferences.

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