Browse Prior Art Database

Channel Initiated Subsystem Diagnostics

IP.com Disclosure Number: IPCOM000077735D
Original Publication Date: 1972-Sep-01
Included in the Prior Art Database: 2005-Feb-25
Document File: 2 page(s) / 13K

Publishing Venue

IBM

Related People

Salmassy, OE: AUTHOR [+2]

Abstract

A set of diagnostic channel command words are defined to extend the effectiveness of a system initiated diagnostic upon I/O subsystems. The command provides control and status collection of an existing set of microdiagnostics. Rigorous testing of a microdiagnostic can be coupled with the data collection and reporting of a system program, to provide a reduction of the diagnostic time consumed by a maintenance engineer and consistently high effectively of diagnosis.

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Channel Initiated Subsystem Diagnostics

A set of diagnostic channel command words are defined to extend the effectiveness of a system initiated diagnostic upon I/O subsystems. The command provides control and status collection of an existing set of microdiagnostics. Rigorous testing of a microdiagnostic can be coupled with the data collection and reporting of a system program, to provide a reduction of the diagnostic time consumed by a maintenance engineer and consistently high effectively of diagnosis.

The basic methods of microdiagnostic initiation includes:
1) Causing the diagnostic loading module to be moved from its

storage area to a suitable storage area

in an associated I/O control.
2) Allowing the movement of the diagnostic from that area over

the channel interface into main CPU storage.
3) Once the diagnostic is buffered in CPU main storage, it may

then be used as a stored data set at the system level.
4) At the control of the system program, the diagnostic may again

be buffered in main CPU storage to be sent back across the

channel to the subsystem.
5) When the diagnostic is sent back to the subsystem controller

area, the resident diagnostic monitor enters the diagnostic

for execution.
6) When the execution completes, the diagnostic stores error

information to a separate log area and then terminates

by exit to the control monitor routine.
7) The error-log area may be moved to main CPU storage. upon

command for error analysis by the system program.

The commands set includes three codes used in accomplishing the above execution. A Diagno...