Many RPG programmers are familiar with the notion of using a variable, rather than a literal, to define the target of a program or procedure call. The problems usually begin when they try to utilize this technique in a /Free program because the “translation” of such calls into /Free is not an obvious one.

The PGMCALL shown below is a simple “old-style” RPG program that demonstrates the basic principle for those of you unfamiliar with the technique. As you can see, it simply requests the name of a program to call, calls the program, and issues an error message if

If you recompile a program while someone’s running it, it’s no big deal. The system moves the old object into library QRPLOBJ and the user never knows the difference. However, creating a display file is a different situation. You can’t replace a display while someone has a lock on it. Here’s a way to replace a display file, even while people are using it.

To illustrate, assume a high-level program, MYHLLPGM, that uses display file MYDSPF. Most likely MYHLLPGM would be written in RPG or maybe COBOL. A user takes a menu option that calls MYHLLPGM, and the system locks

Alongside human tragedies, computer tragedies can also occur when a critical i/OS production system stops working and a shop must unexpectedly rely on its Capacity BackUp (CBU) system as its production box. Because a hard CBU cutover can offer more challenges than a planned switch test, here are some additional configuration tasks that can help you account for the unexpected challenges that go along with an emergency CBU switch over.

When Those Who Stand and Wait No Longer Wait

Like a good insurance policy, you hopefully never have to use your CBU. Unfortunately, there are a number of situations where