 +_____________________________________________________________________
 ] AUTHOR:            ]                             ] DR:              ]
 ] T. METCALF         ]    PASS PROGRAM NOTE        ]    55318         ]
 ]____________________]                             ]__________________]
 ] ORG/PHONE:         ] OPS NOTE ( )  USER NOTE (X) ] DATE: SEPT. 1987 ]
 ] DEV/282-8436       ]      RELEASE NOTE( )        ]  REV: 03/01/89   ]
 ]____________________]_____________________________]__________________]
 ] OI/FLIGHT EFFECTIVITY:        ]  USER AFFECTED:                     ]
 ] OI05 AND SUBS                 ]  CREW (X)  GROUND (X)  DUMP ONLY (X)]
 ]_______________________________]_____________________________________]
 ]        MAJOR SOFTWARE AREA:       ] OPS MODES AFFECTED:             ]
 ]SSW (X)  GNC ( )  VU ( )  SM/PL ( )] 0, G1, G2, G3, G8, G9, S2, S4,  ]
 ]                                   ] PL9                             ]
 ]_____________________________________________________________________]
 ] SOFTWARE SUB-AREA: FTS, I/O, BUS                                    ]
 ]_____________________________________________________________________]
 ] PRINCIPAL FUNCTIONS: SICC                                           ]
 ]_____________________________________________________________________]
 ] TITLE:                                                              ]
 ] POSSIBLE COMMON SET F-T-S DUE TO I/O COMPLETION                     ]
 ]_____________________________________________________________________]
 ] DESCRIPTION:                                                        ]
 ]                                                                     ]
 ] DUE TO POSSIBLE BUS RECONFIGURATION REQUESTS AND PENDING I/O, I/O   ]
 ] COMPLETION COULD BE DISABLED FOR MORE THAN 4 MSEC.  THIS COULD LEAD ]
 ] TO AN F-T-S OF A NON-RS MEMBER.                                     ]
 ]                                                                     ]
 ] IN G9, THE SUPERVISOR CALL INITIATED MFE INPUT CAN COMPLETE NEAR THE]
 ] SYSTEM INTERFACE PROCESS TIMER.  A 5-BUS ERROR CAN DELAY THE SIP    ]
 ] TIMER LONG ENOUGH IN THE RS TO CAUSE TIMEOUT IN THE NON-RS GPC.     ]
 ]                                                                     ]
 ] IN THE RS, IF THE SIP TIMER EXPIRES DURING ICC IPR FOR INPUT ERRORS ]
 ] (E.G. G9 MFE OR THE OPS 3 SVC INITIATED HFE WHICH IS PERFORMED AT   ]
 ] OPS 3 TRANSITION) ICC BUS CONTENTION CAN CAUSE SIP ICC TO BE DELAYED]
 ] LONG ENOUGH TO CAUSE THE NON-RX GPC TO TIMEOUT AT SIP ICC IOC.  THIS]
 ] TYPE OF TIMEOUT COULD RESULT FROM A SINGLE BUS ERROR.  A POSSIBLE   ]
 ] SIGNATURE OF THIS TYPE OF F-T-S WOULD BE ICC CHECKSUM FAILURES LOG- ]
 ] GED AGAINST MEMBERS IN THE RS BY THE NON-RS GPC.                    ]
 ]                                                                     ]
 ] THIS SITUATION WAS FORMERLY OP NOTE 25172/39683/39834/46378.        ]
 ]                                                                     ]
 ]_____________________________________________________________________]
 ] USER RESPONSE:                                                      ]
 ] THE EXPOSURE TO A CS F-T-S CAN BE REDUCED BY ENSURING THAT ALL      ]
 ] OPS RELATED BTU'S/LRU'S ARE POWERED ON TO PRECLUDE UNNECESSARY      ]
 ] INPUT ERROR PROCESSING.                                             ]
 ]                                                                     ]
 ] IF A F-T-S OCCURS, THE USER SHOULD PERFORM STANDARD RESPONSE TO A   ]
 ] NON-RS GPC F-T-S PER ESTABLISHED CREW/LAB PROCEDURES.               ]
 ]_____________________________________________________________________]
 ]CONCURRENCE:                           ]APPROVAL:                    ]
 ]IBM: WYATT COOPER         DATE 04/05/89]                             ]
 ]    --------------------      ---------]                             ]
 ]SSD: W.R. PRUETT          DATE 04/06/89]                             ]
 ]    --------------------      ---------] JACK BOYKIN         04/08/89]
 ]PF MGR: E.A. FOUNTAIN     DATE 04/06/89]------------------- -------- ]
 ]       -----------------      ---------] CHAIRMAN, SASCB      DATE   ]
 ]_______________________________________]_____________________________]
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