Information provided with machine checks

When the hardware detects a failure, it stores the following information about the failure:

The machine check interrupt code (MCIC), which contains:
- Information about the severity of the error
- The time of the error, in relation to the current instruction stream
- An indication of whether the processor has successfully stored additional information about the error
The MCIC is the major interface between the hardware and the operating system, which uses the MCIC to determine what action to take.
The save areas that contain the values of the general, floating point, control, and access registers, the CPU timer, and the clock comparator.
The machine check old program status word (PSW), which contains the PSW at the time of error.
The fixed logout area, which is implemented on only some processor complex models.

See the Principles of Operation for the format and content of the MCIC, register and timer save areas, extended interrupt information, machine check old PSW, and fixed logout area.