gtpd2m11Data Communications Services Reference

CPU Action

When a Unit Record I/O macro is issued, the Unit Record Support CSECT of the TPF system performs error checking to ensure that the macro entry requirements are met. If the macro is validly issued, the Unit Record Support CSECT queues the I/O request, initiates the I/O operation, processes the subsequent interrupts, resets status indicators at I/O completion and performs error recovery when required. See TPF General Macros for a description of the functions performed by the unit record macros.