Use the input/output instructions (instead of the IBM-supplied system macro instructions) when you want to control your input and output operations more closely.

The input or output instructions let you identify the channel or the device on which the input or output operation is to be done. For information about how and when you can use these instructions, see the applicable system manual.

For more information, see "Input/Output Operations" in the applicable z/Architecture Principles of Operation manual and the applicable system manuals.