 +_____________________________________________________________________
 ] AUTHOR:            ]                             ] SMS:  D031       ]
 ] P. WILSON          ]    BFS PROGRAM NOTE         ] DR : 55331       ]
 ]____________________]                             ]__________________]
 ] ORG/PHONE:         ] OPS NOTE ( )  USER NOTE (X) ] DATE : 10/04/84  ]
 ] RI/KSC/1-4656      ]      RELEASE NOTE ( )       ] REV A: 10/20/94  ]
 ]____________________]_____________________________]__________________]
 ] OI/FLIGHT EFFECTIVITY:        ]  USER AFFECTED:                     ]
 ] ALL                           ]  CREW (X)  GROUND (X)  DUMP ONLY ( )]
 ]_______________________________]_____________________________________]
 ]           MAJOR SOFTWARE AREA:            ] OPS MODES AFFECTED:     ]
 ]BSL( )BSS( )GNC( )SEQ( )SMSP( )IPL( )DCP(X)] ALL                     ]
 ]_____________________________________________________________________]
 ] SOFTWARE SUB-AREA: DCP                                              ]
 ]_____________________________________________________________________]
 ] PRINCIPAL FUNCTIONS: MG017300                                       ]
 ]_____________________________________________________________________]
 ] TITLE: INVALID KEYCODES (POSSIBLE POLL FAIL)                        ]
 ]_____________________________________________________________________]
 ] DESCRIPTION:                                                        ]
 ] THERE IS A KNOWN 1.2 MICRO-SECOND WINDOW DURING WHICH THE DEU IS    ]
 ] SUSCEPTIBLE TO INVALID KEYCODES INPUT FROM THE KEYBOARD ADAPTER     ]
 ] UNIT. THE DCP SENSES THE PROBLEM AND SETS THE MEMORY PARITY AND CPU ]
 ] SELF-TEST ERROR BITS IN THE S/W STATUS WORD, AND THE CRITICAL BITE  ]
 ] INDICATOR IN THE POLL RESPONSE HEADERWORD.                          ]
 ]                                                                     ]
 ] FOR PASS, THIS CAUSES THE COMMANDING GPC TO ANNUNCIATE A 'CRT BITE  ]
 ] X' FAULT MESSAGE AND TERMINATE POLLING OF THE DEU. 'POLL FAIL' WILL ]
 ] BE DISPLAYED IN THE LOWER RIGHT CORNER OF THE CRT. 'ERR' WILL BE    ]
 ] DISPLAYED MOMENTARILY ON THE SCRATCH PAD LINE (SPL) PRIOR TO THE    ]
 ] 'POLL FAIL'.                                                        ]
 ]                                                                     ]
 ] FOR BFS, A 'CRT BITE X' FAULT MESSAGE WILL BE ANNUNCIATED           ]
 ] REGARDLESS OF WHETHER THE COMMANDING GPC IS PASS OR BFS. FOR A BFS- ]
 ] CONTROLLED DEU, 'ERR' WILL BE DISPLAYED ON THE SPL AND DEU POLLING  ]
 ] WILL NOT BE TERMINATED.                                             ]
 ]_____________________________________________________________________]
 ] USER RESPONSE:                                                      ]
 ] USE THE OTP TO OBTAIN THE DATA NECESSARY TO VERIFY THIS CONDITION   ]
 ] AS FOLLOWS:                                                         ]
 ]                                                                     ]
 ]  'ITEM D + 0F49'     DISPLAY THE KEYCODE ERROR AND ERROR REGISTER   ]
 ]                      BUFFERS. RECORD THE DATA.                      ]
 ]  'ITEM E EXEC'       EXIT THE OTP.                                  ]
 ]  'ITEM A EXEC'       RE-INITIALIZE THE DEU.                         ]
 ]                                                                     ]
 ]          ---  SEE SUPPLEMENTAL SHEET ---                            ]
 ]_____________________________________________________________________]
 ]CONCURRENCE:                           ]APPROVAL:                    ]
 ]RI    : G. ALBRIGHT       DATE 10/28/94]                             ]
 ]       -----------------      ---------]                             ]
 ]ASD   : ERIC C. BINGHAM   DATE 12/06/94]                             ]
 ]       -----------------      ---------] DARRELL E. STAMPER 12/08/94 ]
 ]PF MGR: DAVE STEPHENSON   DATE 12/06/94]------------------- -------- ]
 ]       -----------------      ---------] CHAIRMAN, SASCB      DATE   ]
 ]_____________________________________________________________________]
 @

1+_____________________________________________________________________
 ]                                                                     ]
 ]                       SUPPLEMENTAL SHEET                            ]
 ]                                                                     ]
 ]_____________________________________________________________________]
 ] AUTHOR:            ]                             ] SMS:  D031       ]
 ] P. WILSON          ]    BFS PROGRAM NOTE         ] DR : 55331       ]
 ]____________________]                             ]__________________]
 ] ORG/PHONE:         ] OPS NOTE ( )  USER NOTE (X) ] DATE : 10/04/84  ]
 ] RI/KSC/1-4656      ]      RELEASE NOTE ( )       ] REV A: 10/20/94  ]
 ]____________________]_____________________________]__________________]
 ] TITLE: INVALID KEYCODES (POSSIBLE POLL FAIL)                        ]
 ]                                                                     ]
 ]                                                                     ]
 ]_____________________________________________________________________]
 ] DESCRIPTION:                                                        ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]_____________________________________________________________________]
 ] USER RESPONSE:                                                      ]
 ]                                                                     ]
 ] FOR PASS ONLY (USING AN ALTERNATE DEU/KYBD) :                       ]
 ]  'GPC/CRT 0N EXEC'   ISOLATE DEU(N).                                ]
 ]  'GPC/CRT YN EXEC'   ASSIGN DEU(N) TO GPC(Y). RE-ESTABLISH POLLING. ]
 ]                                                                     ]
 ] FOR THE 1.2 MICRO-SECOND WINDOW PROBLEM, THE CONTENTS OF LOCATION   ]
 ] 0F56 WILL EQUAL 0102 AND LOCATION 0F50 WILL EQUAL ANY INVALID       ]
 ] KEYCODE.                                                            ]
 ]                                                                     ]
 ] IF THE ERROR PERSISTS, THE DEU AND/OR KEYBOARD SHOULD BE SUSPECTED  ]
 ] OF A HARD FAILURE AND APPROPRIATE ACTION TAKEN.                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]_____________________________________________________________________]
 @
