 +_____________________________________________________________________
 ] AUTHOR:            ]                             ] DR:              ]
 ] PAUL TICE          ]    PASS PROGRAM NOTE        ]       101757     ]
 ]____________________]                             ]__________________]
 ] ORG/PHONE:         ] OPS NOTE ( )  USER NOTE (X) ] DATE:  03/28/90  ]
 ] IBM/282-7297       ]      RELEASE NOTE( )        ] REV A: 01/25/91  ]
 ]____________________]_____________________________]__________________]
 ] OI/FLIGHT EFFECTIVITY:        ]  USER AFFECTED:                     ]
 ] OI8C AND SUBS                 ]  CREW (X)  GROUND (X)  DUMP ONLY ( )]
 ]_______________________________]_____________________________________]
 ]        MAJOR SOFTWARE AREA:       ] OPS MODES AFFECTED:             ]
 ]SSW (X)  GNC ( )  VU ( )  SM/PL ( )] G1, G2, G3, G6, G8, G9          ]
 ]_____________________________________________________________________]
 ] SOFTWARE SUB-AREA:    ANNUNCIATION                                  ]
 ]_____________________________________________________________________]
 ] PRINCIPAL FUNCTIONS:  SANU                                          ]
 ]_____________________________________________________________________]
 ] TITLE: I/O ERROR ANNUNCIATED BY NON-DETECTING GPCS                  ]
 ]_____________________________________________________________________]
 ] DESCRIPTION:                                                        ]
 ] A BTU SEGMENT OR BCE ELEMENT BYPASS MESSAGE MAY BE ANNUNCIATED BY   ]
 ] NON-DETECTING RS GPCS.  THIS SITUATION ARISES WHEN MULTIPLE I/O     ]
 ] ERRORS ARE DETECTED ON THE SAME MULTI-BUS I/O TRANSACTION AND AT    ]
 ] LEAST ONE OF THE I/O ERRORS IS DETECTED BY MORE THAN ONE BUT NOT ALL]
 ] GPCS (NOT UNIVERSAL).  FOR EXAMPLE, IF GPCS 1 & 2 DETECT AN I/O     ]
 ] ERROR ON ONE BUS AND ALL RS GPCS (1-4) DETECT AN ERROR ON ANOTHER   ]
 ] BUS WITHIN THE SAME I/O TRANSACTION, ALL GPCS WILL ANNUNCIATE THE   ]
 ] UNIVERSAL I/O ERROR AS EXPECTED BUT GPCS 3 & 4 WILL ANNUNCIATE THE  ]
 ] I/O ERROR DETECTED BY ONLY GPC 1 AND 2.  THAT IS, BOTH MESSAGES     ]
 ] WILL BE ANNUNCIATED BY ALL RS GPCS (1-4).                           ]
 ]                                                                     ]
 ] I/O ERROR LOG ENTRIES IN EACH GPC WILL ACCURATELY REFLECT WHAT EACH ]
 ] GPC DETECTED. NOTE THAT THE LAST I/O ERROR LOGGED BY EACH GPC (WHICH]
 ] IS THEN ICC'D AND DOWNLISTED) MAY NOT BE IN AGREEMENT. IN THE ABOVE ]
 ] EXAMPLE, IF THE UNIVERSAL I/O ERROR OCCURS ON A HIGHER NUMBERED BUS ]
 ] THAN THE BUS OF THE NOT UNIVERSAL I/O ERROR, THE LAST LOG ENTRY IN  ]
 ] ALL RS GPCS WOULD AGREE (BUT THEY WOULDN'T IN THE REVERSE CASE).    ]
 ] ALSO, THE I/O ERROR LOG COUNTS MAY OR MAY NOT AGREE DEPENDING ON    ]
 ] THE EXACT SCENARIO. IN THE ABOVE EXAMPLE, GPCS 1 & 2 WOULD LOG ONE  ]
 ] MORE I/O ERROR THAN GPCS 3 & 4.  FOR THE CASE OF TWO NOT UNIVERSAL  ]
 ] I/O ERRORS, ONE DETECTED BY GPCS 1 & 2 AND THE OTHER DETECTED BY    ]
 ] GPCS 3 & 4 ON THE SAME TRANSACTION, I/O ERROR COUNTS WOULD AGREE.   ]
 ]                                                                     ]
 ]                                                                     ]
 ]                 - CONTINUED ON SUPPLEMENT PAGE -                    ]
 ]                                                                     ]
 ]                                                                     ]
 ]_____________________________________________________________________]
 ]CONCURRENCE:                           ]APPROVAL:                    ]
 ]IBM: PATTI A. THORNTON    DATE 03/12/91]                             ]
 ]    --------------------      ---------]                             ]
 ]FDSD:   W. R. PRUETT      DATE 03/12/91]                             ]
 ]     -------------------      ---------] DARRELL E. STAMPER 03/13/91 ]
 ]PF MGR:ELIZABETH FOUNTAIN DATE 03/12/91]------------------- -------- ]
 ]       ------------------     ---------] CHAIRMAN, SASCB      DATE   ]
 ]_______________________________________]_____________________________]
 @





 +_____________________________________________________________________
 ]                                                                     ]
 ]                       SUPPLEMENTAL SHEET                            ]
 ]                                                                     ]
 ]_____________________________________________________________________]
 ] AUTHOR:            ]                             ] DR:              ]
 ] PAUL TICE          ]    PASS PROGRAM NOTE        ]       101757     ]
 ]____________________]                             ]__________________]
 ] ORG/PHONE:         ] OPS NOTE ( )  USER NOTE (X) ] DATE:  03/28/90  ]
 ] IBM/282-7297       ]      RELEASE NOTE( )        ] REV A: 01/25/91  ]
 ]____________________]_____________________________]__________________]
 ] OI/FLIGHT EFFECTIVITY:        ]  USER AFFECTED:                     ]
 ] OI8C AND SUBS                 ]  CREW (X)  GROUND (X)  DUMP ONLY ( )]
 ]_______________________________]_____________________________________]
 ] TITLE:                                                              ]
 ]        I/O ERROR ANNUNCIATED BY NON-DETECTING GPCS                  ]
 ]                                                                     ]
 ]_____________________________________________________________________]
 ] DESCRIPTION:                                                        ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]_____________________________________________________________________]
 ]USER RESPONSE:                                                       ]
 ] BE AWARE THAT FOR THE ABOVE SITUATIONS, THE I/O ERROR LOGS AND      ]
 ] FAULT MESSAGES WILL NOT AGREE ON THE GPCS EXPERIENCING THE ERROR(S).]
 ] THE I/O ERROR LOGS AND COUNTS FROM EACH GPC SHOULD BE COMPARED TO   ]
 ] IDENTIFY THE PARTICULAR SCENARIO INVOLVED.  AS WITH NON-UNIVERSAL   ]
 ] I/O ERROR CASES, I/O RESETS AND PORT MODING OR RESTRINGING OF THE   ]
 ] STRING ASSOCIATED WITH THE NOT UNIVERSALLY-DETECTED I/O ERROR(S)    ]
 ] SHOULD NOT BE PERFORMED.  THESE ACTIONS MAY CAUSE A NON-UNIVERSAL   ]
 ] I/O ERROR RESULTING IN AN RS FAIL-TO-SYNC.  NOTE THAT WITHOUT       ]
 ] GROUND ANALYSIS, THE CREW WILL NOT KNOW THAT ONE OF THE ABOVE       ]
 ] SITUATIONS HAS OCCURRED.                                            ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]_____________________________________________________________________]
 @
