"Virtual RPG Machine" Will Aid Porting

Over the past year, Java Virtual Machine on the AS/400 has become a reality, opening the platform to potentially thousands of new applications. Now, one tool vendor is twisting the equation around-offering a "Virtual RPG Machine" that will enable other platforms to run AS/400 applications. That's how CrossWorks Inc. (Minneapolis) is positioning the latest version of its Cross400 compiler and development tool suite. To smooth the transition even further, CrossWorks also announced it has added a utility that automatically generates a Windows interface once the RPG application is re-compiled.

"The primary audience for the tool is ISVs looking to quickly deliver Windows NT or Unix versions of their products," says David Schindler, VP of business development for CrossWorks. "As Windows NT servers and networks proliferate at end-user companies, ISVs will be under heavy demand to deliver such porting." Similar capabilities are offered through California Software Inc. (Santa Ana, Calif.) and Aldon Computer Group (Oakland, Calif.).

With the Virtual RPG Machine installed on a PC server or Unix box, "We're bringing the Java model to RPG. RPG applications can run unmodified," says Schindler. "They're complied into a binary object. The RPG Virtual Machine sits above the machine interface level on all platforms, because a separate release for each operating system would be required." RPG applications will essentially run unmodified on Windows NT and Unix systems, he states adding, "This makes RPG no different than C++, Fortran, COBOL, or Java."

While there has been a lot of attention on Java as a cross-platform language, Java applications tend to be more inefficient than RPG, Schindler explains. "The issue is performance with Java. It's a relatively slow language. Sun envisioned Java to be compatible at the binary level on all platforms, but the object cannot be optimized for all platforms."

Essentially, the only change to the application when it is re-platformed is in the user interface, which only comprises five to ten percent of the total code, he adds. CrossWorks' automatic GUI transforms traditional green-screen application interfaces into a Windows-like interface with no modification needed to the underlying code. The tool automatically reads the applications DDS specs at run-time and transforms them into graphical formats.

CrossWorks also has included a utility for users that want graphical capabilities above and beyond what is capable within DDS or RPG. The new Menu Builder enables users to graphically re-design their menus by creating a short script file.