Navigating the I/O configuration windows

The Input/Output Configuration window is the starting point for all of the stand-alone IOCP functions.

There are four user I/O configuration data sets, identified as A0 through A3. These data sets have names that you, as the system owner, supply. The fifth data set, D0, is a diagnostic data set. D0 cannot be altered. It is intended for service personnel to use, with the following possible exception. If you are on a coupling facility or cannot perform a power-on reset using any of the A0 through A3 data sets, you can use D0 to perform the power-on reset. You cannot access I/O after a D0 power-on reset.

If a data set is displayed on the IOCDS matching hardware system area (HSA) line, that data set is a dynamic-capable IOCDS, which is equivalent to the I/O configuration in the hardware system area (HSA). A dynamic-capable IOCDS is one written using the HCD software tool on z/OS® or VM or when calling the IOCP CMS utility with privilege class B for VM. If a data set is displayed on the Active input/output configuration data set (IOCDS) line, that data set has a Data Set Status of Active.

The Input/Output Configuration window has an Options menu (see Figure 1) that you can use to change the status or the content of the selected I/O configuration. The Input/Output Configuration window and the Options and View menus are all explained in greater detail on the following pages. The important point here is that this window provides access to all of the information about the configuration data sets currently available on the system, and the Options menu permits you to change that information.