1+_____________________________________________________________________
 ] AUTHOR:            ]                             ] DR:              ]
 ] C.E. ORTIZ-LONGO   ]    PASS PROGRAM NOTE        ]       106679     ]
 ]____________________]                             ]__________________]
 ] ORG/PHONE:         ] OPS NOTE ( )  USER NOTE (X) ] DATE:            ]
 ] IBM/282-8551       ]      RELEASE NOTE( )        ]       01/20/94   ]
 ]____________________]_____________________________]__________________]
 ] OI/FLIGHT EFFECTIVITY:        ]  USER AFFECTED:                     ]
 ] OI-21 AND SUBS                ]  CREW (X)  GROUND (X)  DUMP ONLY ( )]
 ]_______________________________]_____________________________________]
 ]        MAJOR SOFTWARE AREA:       ] OPS MODES AFFECTED:             ]
 ]SSW (X)  GNC ( )  VU ( )  SM/PL ( )]  ALL                            ]
 ]_____________________________________________________________________]
 ] SOFTWARE SUB-AREA: I/O, MMU, OPS, TRANSITIONS                       ]
 ]_____________________________________________________________________]
 ] PRINCIPAL FUNCTIONS: SBIO                                           ]
 ]_____________________________________________________________________]
 ] TITLE:                                                              ]
 ]        EFFECTS OF TRANSMITTER/RECEIVER FAILURES ON MMU OVERLAYS     ]
 ]_____________________________________________________________________]
 ] DESCRIPTION:                                                        ]
 ]                                                                     ]
 ]  NOTE:  THE INTENT OF THIS USER NOTE IS TO EXPLAIN THE UNIQUE ERROR ]
 ]         SIGNATURES ASSOCIATED WITH GPC/BCE HARDWARE TRANSMITTER AND ]
 ]         RECEIVER-RELATED FAILURES DURING MMU OVERLAYS.              ]
 ]                                                                     ]
 ]  TRANSMITTER-RELATED FAILURES                                       ]
 ]  ============================                                       ]
 ]                                                                     ]
 ]  A. ON THE COMMANDER GPC:                                           ]
 ]                                                                     ]
 ]  A BUS 18 OR 19 MIA TRANSMITTER OR TRANSMITTER ENABLE BIT FAILURE,  ]
 ]  ON THE PRIMARY MMU BUS OF THE GPC COMMANDER OF THE MMU OVERLAY WILL]
 ]  RESULT IN AN OVERLAY FAILURE ON THE PRIMARY MMU AND A SWITCH-OVER  ]
 ]  TO THE ALTERNATE MMU.  THE OVERLAY READ WILL BE SUCCESSFUL IF NO   ]
 ]  ERROR IS ENCOUNTERED ON THE ALTERNATE MMU.  FOR AN MMU SWITCH-OVER,]
 ]  A TRANSMITTER OR TRANSMITTER ENABLE BIT FAILURE ON THE ALTERNATE   ]
 ]  MMU ON THE GPC COMMANDER OF THE MMU OVERLAY WILL RESULT IN NO GPC  ]
 ]  SUCCESSFULLY COMPLETING THE OPS TRANSITION.                        ]
 ]                                                                     ]
 ]                  -- CONTINUED ON SUPPLEMENT PAGES --                ]
 ]                                                                     ]
 ]_____________________________________________________________________]
 ]USER RESPONSE:                                                       ]
 ]                                                                     ]
 ]  BE AWARE OF THESE ERROR SIGNATURES.                                ]
 ]                                                                     ]
 ]_____________________________________________________________________]
 ]CONCURRENCE:                           ]APPROVAL:                    ]
 ]IBM:   JEAN L. ZOPHY      DATE 02/15/94]                             ]
 ]    --------------------      ---------]                             ]
 ]FDSD:ELIZABETH A.FOUNTAIN DATE 02/15/94]                             ]
 ]    ----------------------    ---------] DARRELL E. STAMPER 02/15/94 ]
 ]PF MGR: ERIC C. BINGHAM   DATE 02/15/94]------------------- -------- ]
 ]       -----------------      ---------] CHAIRMAN, SASCB      DATE   ]
 ]_______________________________________]_____________________________]
 @






1+_____________________________________________________________________
 ]                                                                     ]
 ]                       SUPPLEMENTAL SHEET                            ]
 ]                                                                     ]
 ]_____________________________________________________________________]
 ] AUTHOR:            ]                             ] DR:              ]
 ] C.E. ORTIZ-LONGO   ]    PASS PROGRAM NOTE        ]       106679     ]
 ]____________________]                             ]__________________]
 ] ORG/PHONE:         ] OPS NOTE ( )  USER NOTE (X) ] DATE:            ]
 ] IBM/282-8551       ]      RELEASE NOTE( )        ]       01/20/94   ]
 ]____________________]_____________________________]__________________]
 ] TITLE:                                                              ]
 ]        EFFECTS OF TRANSMITTER/RECEIVER FAILURES ON MMU OVERLAYS     ]
 ]                                                                     ]
 ]_____________________________________________________________________]
 ] DESCRIPTION:                                                        ]
 ]                                                                     ]
 ]  TRANSMITTER-RELATED FAILURES (CONTINUED)                           ]
 ]  =============================                                      ]
 ]                                                                     ]
 ]  FOR A BUS 18 OR 19 MIA TRANSMITTER FAILURE ON THE GPC COMMANDER OF ]
 ]  THE MMU OPS TRANSITION, THE ERROR SIGNATURES FOR THE COMMANDER GPC ]
 ]  ARE:                                                               ]
 ]  (A) ITO WITH A RESIDUAL WORD COUNT (RWC) EQUAL 2 AND "I/O ERROR    ]
 ]      MMUX" (PREPOSITION),                                           ]
 ]  (B) ITO WITH A RWC EQUAL 2 AND "I/O ERROR MMUX" (STATUS READ/POSI- ]
 ]      TION TAPE),                                                    ]
 ]  (C) ITO WITH A RWC EQUAL TO THE WORD COUNT IN THE FIRST LOAD BLOCK ]
 ]      BEING READ AND "I/O ERROR MMUX" (OVERLAY READ), AND            ]
 ]  (D) SIGNATURES B AND C ON THE OVERLAY READ RETRY.                  ]
 ]  EXPECTED RS LISTENER GPC ERROR SIGNATURES ARE:  A (ONLY IF LISTENER]
 ]  GPC PARTICIPATED IN PREPOSITION), B AND C ABOVE PER OVERLAY READ   ]
 ]  ATTEMPT.  NOTE THAT SOME FAULT MESSAGES MAY BE PRECLUDED BY THE    ]
 ]  4.8 SECOND INTER-LOCK (REF. USER NOTE 28364).                      ]
 ]                                                                     ]
 ]  FOR A BUS 18 OR 19 MIA TRANSMITTER ENABLE BIT FAILURE ON THE GPC   ]
 ]  COMMANDER OF THE MMU OPS TRANSITION, THE ERROR SIGNATURES FOR THE  ]
 ]  COMMANDER GPC ARE:  BCE DETECTED "TRANSMITTER DISABLED" NO/GO      ]
 ]  CONDITION (23RD BIT IN THE IOP STATUS REG) DETECTED DURING THE     ]
 ]  PREPOSITION, THE STATUS READ/POSITION TAPE, AND THE OVERLAY READ.  ]
 ]  ALSO UP TO 3 "I/O ERROR MMUX" FAULT MESSAGES ARE ANNUNCIATED.      ]
 ]  EXPECTED RS LISTENER GPC ERROR SIGNATURES ARE ITOS DURING THE      ]
 ]  PREPOSITION (ONLY IF LISTENER GPC PARTICIPATED IN PREPOSITION),    ]
 ]  STATUS READ/POSITION TAPE AND OVERLAY READ.  THIS FAILURE PREVENTS ]
 ]  THE AFFECTED BCE FROM FUNCTIONING PROPERLY WHEN THE GPC IS EITHER  ]
 ]  THE COMMANDER OR LISTENER OF THE MMU OVERLAY.  LISTENER GPC        ]
 ]  TRANSMITTER RELATED FAILURES ARE EXPLAINED BELOW.                  ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]                  -- CONTINUED ON SUPPLEMENT PAGES --                ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]_____________________________________________________________________]
 @





1+_____________________________________________________________________
 ]                                                                     ]
 ]                       SUPPLEMENTAL SHEET                            ]
 ]                                                                     ]
 ]_____________________________________________________________________]
 ] AUTHOR:            ]                             ] DR:              ]
 ] C.E. ORTIZ-LONGO   ]    PASS PROGRAM NOTE        ]       106679     ]
 ]____________________]                             ]__________________]
 ] ORG/PHONE:         ] OPS NOTE ( )  USER NOTE (X) ] DATE:            ]
 ] IBM/282-8551       ]      RELEASE NOTE( )        ]       01/20/94   ]
 ]____________________]_____________________________]__________________]
 ] TITLE:                                                              ]
 ]        EFFECTS OF TRANSMITTER/RECEIVER FAILURES ON MMU OVERLAYS     ]
 ]                                                                     ]
 ]_____________________________________________________________________]
 ] DESCRIPTION:                                                        ]
 ]                                                                     ]
 ]  TRANSMITTER-RELATED FAILURES (CONTINUED)                           ]
 ]  =============================                                      ]
 ]                                                                     ]
 ]  B. ON A LISTENER GPC:                                              ]
 ]                                                                     ]
 ]  A BUS 18 OR 19 MIA TRANSMITTER FAILURE IN A RS LISTENER GPC        ]
 ]  RESULTS IN NO ERROR.                                               ]
 ]                                                                     ]
 ]  A BUS 18 OR 19 MIA TRANSMITTER ENABLE BIT FAILURE IN A RS LISTENER ]
 ]  GPC WILL RESULT IN THAT GPC FAILING THE MMU OPS TRANSITION.  THIS  ]
 ]  IS BECAUSE THE LISTENER GPC BCE PROGRAM CONTAINS RDLI INSTRUCTIONS ]
 ]  THAT WILL EXECUTE DIFFERENTLY IF THE TRANSMITTER ENABLE BIT IS NOT ]
 ]  ENABLED (BCE IN LISTENER MODE).  THIS PRECLUDES PROPER RECEIPT OF  ]
 ]  THE MMU OVERLAY.  MMU I/O DESIGN ASSUMES THAT BUS 18 AND 19 MIA    ]
 ]  TRANSMITTER ENABLE BITS ARE ALWAYS SET TO ONE (ENABLED) IN ALL     ]
 ]  GPCS.  ERROR SIGNATURES ARE:                                       ]
 ]  (A) ITO WITH A RWC EQUAL TO THE WORD COUNT OF THE SECOND LOAD      ]
 ]      BLOCK OF THE OVERLAY (OI22 PRIOR TO DR106998 FIX FOR MULTI-    ]
 ]      TRACK OVERLAYS),                                               ]
 ]  (B) SYNC MISMATCH (OI22 AND SUBS AFTER THE DR106998 FIX FOR MULTI- ]
 ]      TRACK OVERLAYS), OR                                            ]
 ]  (C) MSC T/O (FOR OVERLAYS WITH NO TRACK CROSSOVERS).               ]
 ]  THIS FAILURE PREVENTS THE AFFECTED BCE FROM FUNCTIONING PROPERLY   ]
 ]  WHEN THE GPC IS EITHER THE COMMANDER OR A LISTENER OF THE MMU      ]
 ]  OVERLAY.  COMMANDER GPC TRANSMITTER RELATED FAILURES ARE EXPLAINED ]
 ]  ABOVE.                                                             ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]                  -- CONTINUED ON SUPPLEMENT PAGES --                ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]_____________________________________________________________________]
 @





1+_____________________________________________________________________
 ]                                                                     ]
 ]                       SUPPLEMENTAL SHEET                            ]
 ]                                                                     ]
 ]_____________________________________________________________________]
 ] AUTHOR:            ]                             ] DR:              ]
 ] C.E. ORTIZ-LONGO   ]    PASS PROGRAM NOTE        ]       106679     ]
 ]____________________]                             ]__________________]
 ] ORG/PHONE:         ] OPS NOTE ( )  USER NOTE (X) ] DATE:            ]
 ] IBM/282-8551       ]      RELEASE NOTE( )        ]       01/20/94   ]
 ]____________________]_____________________________]__________________]
 ] TITLE:                                                              ]
 ]        EFFECTS OF TRANSMITTER/RECEIVER FAILURES ON MMU OVERLAYS     ]
 ]_____________________________________________________________________]
 ] DESCRIPTION:                                                        ]
 ]                                                                     ]
 ]  RECEIVER-RELATED FAILURES                                          ]
 ]  =========================                                          ]
 ]                                                                     ]
 ]  A. ON THE COMMANDER GPC:                                           ]
 ]                                                                     ]
 ]  A BUS 18 OR 19 MIA RECEIVER OR RECEIVER ENABLE BIT FAILURE ON THE  ]
 ]  PRIMARY MMU BUS OF THE GPC COMMANDER OF THE MMU OVERLAY WILL RESULT]
 ]  IN AN OVERLAY FAILURE ON THE PRIMARY MMU AND A SWITCH-OVER TO THE  ]
 ]  ALTERNATE MMU.  OVERLAY READ WILL BE SUCCESSFUL IF NO ERROR IS     ]
 ]  ENCOUNTERED ON THE ALTERNATE MMU.                                  ]
 ]                                                                     ]
 ]  A SWITCH-OVER TO THE ALTERNATE MMU WITH A BUS 18 OR 19 MIA         ]
 ]  RECEIVER OR RECEIVER ENABLE BIT FAILURE ON THE GPC COMMANDER OF    ]
 ]  THE MMU OVERLAY WILL POSSIBLY RESULT IN NO GPC SUCCESSFULLY        ]
 ]  COMPLETING THE MMU OPS TRANSITION.  THE GPC COMMANDER OF THE MMU   ]
 ]  OPS TRANSITION WILL FAIL TO TRANSITION.  RS LISTENER GPCS WILL     ]
 ]  ONLY FAIL UNDER THE CONDITIONS EXPLAINED LATER.                    ]
 ]                                                                     ]
 ]  FOR THE ABOVE TWO CASES, IF AN ERROR IS ENCOUNTERED THE ERROR      ]
 ]  SIGNATURES FOR THE COMMANDER GPC ARE:                              ]
 ]  (A) ITO WITH A RWC EQUAL 2 AND A "I/O ERROR MMUX" (PREPOSITION),   ]
 ]  (B) ITO WITH A RWC EQUAL 2 AND A "I/O ERROR MMUX" (STATUS          ]
 ]      READ/POSITION TAPE),                                           ]
 ]  (C) ITO WITH A RWC EQUAL TO THE WORD COUNT IN THE FIRST LOAD BLOCK ]
 ]      BEING READ AND A "I/O ERROR MMUX" (OVERLAY READ),              ]
 ]  (D) A DOWNLISTED MMU BITE REGISTER-A EQUAL 2000 (ON/PAST LOCATION  ]
 ]      ERROR), ONLY IF THE PHASE TO READ IS NOT IN THE RIGHT          ]
 ]      DIRECTION, AND                                                 ]
 ]  (E) SIGNATURES B, C, AND D ON THE OVERLAY READ RETRY.              ]
 ]  NOTE THAT SOME FAULT MESSAGES MAY BE PRECLUDED BY THE 4.8 SECOND   ]
 ]  INTER-LOCK (REF. USER NOTE 28364).                                 ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]                  -- CONTINUED ON SUPPLEMENT PAGES --                ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]_____________________________________________________________________]
 @





1+_____________________________________________________________________
 ]                                                                     ]
 ]                       SUPPLEMENTAL SHEET                            ]
 ]                                                                     ]
 ]_____________________________________________________________________]
 ] AUTHOR:            ]                             ] DR:              ]
 ] C.E. ORTIZ-LONGO   ]    PASS PROGRAM NOTE        ]       106679     ]
 ]____________________]                             ]__________________]
 ] ORG/PHONE:         ] OPS NOTE ( )  USER NOTE (X) ] DATE:            ]
 ] IBM/282-8551       ]      RELEASE NOTE( )        ]       01/20/94   ]
 ]____________________]_____________________________]__________________]
 ] TITLE:                                                              ]
 ]        EFFECTS OF TRANSMITTER/RECEIVER FAILURES ON MMU OVERLAYS     ]
 ]                                                                     ]
 ]_____________________________________________________________________]
 ] DESCRIPTION:                                                        ]
 ]                                                                     ]
 ]  RECEIVER-RELATED FAILURES (CONTINUED)                              ]
 ]  =========================                                          ]
 ]                                                                     ]
 ]  RS LISTENER GPCS WILL EXPERIENCE AN ERROR DURING EACH OVERLAY READ ]
 ]  ATTEMPT ONLY IF:                                                   ]
 ]  (A) THE PHASE TO BE READ IS NOT IN THE RIGHT TAPE DIRECTION DUE TO ]
 ]      COMMANDER GPC NOT BEING ABLE TO ISSUE THE POSITION TAPE COMMAND]
 ]      WHEN IT ENCOUNTERED AN ITO DURING THE STATUS READ.  ERROR      ]
 ]      SIGNATURE:  ITO EQUAL TO WORD COUNT OF FIRST LOAD BLOCK TO READ]
 ]      AND A MMU BITE REGISTER-A EQUAL 2000, OR                       ]
 ]  (B) A MULTI-TRACK PHASE OVERLAY READ IS BEING PERFORMED.  THIS IS  ]
 ]      DUE TO THE COMMANDER GPC NOT BEING ABLE TO ISSUE CHANGE OF     ]
 ]      TRACK MMU COMMANDS WHEN IT ENCOUNTERED AN ITO DURING THE       ]
 ]      OVERLAY READ.  ERROR SIGNATURE:  INTER-WORD T/O WITH A RWC     ]
 ]      EQUAL TO THE WORD COUNT MINUS 1 OF THE FIRST LOAD BLOCK OF     ]
 ]      THE SECOND TRACK BEING READ.                                   ]
 ]  THIS FAILURE PREVENTS THE AFFECTED BCE FROM FUNCTIONING PROPERLY   ]
 ]  WHEN THE GPC IS EITHER THE COMMANDER OR A LISTENER OF THE MMU      ]
 ]  OVERLAY.  LISTENER GPC RECEIVER RELATED FAILURES ARE EXPLAINED     ]
 ]  BELOW.                                                             ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]  B. ON A LISTENER GPC:                                              ]
 ]                                                                     ]
 ]  A BUS 18 OR 19 MIA RECEIVER OR RECEIVER ENABLE BIT FAILURE ON A    ]
 ]  LISTENER RS GPC WILL RESULT IN ONLY THAT GPC FAILING THE MMU OPS   ]
 ]  TRANSITION (I.E., THE COMMANDER AND LISTENER GPCS WITHOUT THE      ]
 ]  FAILURE WILL TRANSITION SUCCESSFULLY).  ERROR SIGNATURES ARE:      ]
 ]  (A) ITO WITH A RWC EQUAL 2 (ONLY IF LISTENER GPC PARTICIPATED      ]
 ]      IN PREPOSITION),                                               ]
 ]  (B) ITO WITH A RWC EQUAL 2 (STATUS READ/POSITION TAPE), AND        ]
 ]  (C) ITO WITH A RWC EQUAL THE WORD COUNT OF THE FIRST LOAD BLOCK TO ]
 ]      READ.                                                          ]
 ]  THIS FAILURE PREVENTS THE AFFECTED BCE FROM FUNCTIONING PROPERLY   ]
 ]  WHEN THE GPC IS EITHER THE COMMANDER OR A LISTENER OF THE MMU      ]
 ]  OVERLAY.  COMMANDER GPC RECEIVER RELATED FAILURES ARE EXPLAINED    ]
 ]  ABOVE.                                                             ]
 ]                                                                     ]
 ]_____________________________________________________________________]
 @
