 +_____________________________________________________________________
  AUTHOR:                                          DR:              
  PAUL TICE              PASS PROGRAM NOTE             33268        
 ____________________                             __________________
  ORG/PHONE:          OPS NOTE ( )  USER NOTE (X)  DATE:  JUNE 1988 
  LSIS/282-7297            RELEASE NOTE( )         REV C: 09/28/95  
 ___________________________________________________________________
  OI/FLIGHT EFFECTIVITY:          USER AFFECTED:                     
  OI-8D AND SUBS                  CREW (X)  GROUND (X)  DUMP ONLY ( )
 ____________________________________________________________________
         MAJOR SOFTWARE AREA:        OPS MODES AFFECTED:             
 SSW (X)  GNC ( )  VU ( )  SM/PL ( ) 0, G1, G2, G3, G6, G8, G9, S2   
                                     S4, P9                          
 _____________________________________________________________________
  SOFTWARE SUB-AREA: LDB, OPS, TRANSITIONS, MMU                       
 _____________________________________________________________________
  PRINCIPAL FUNCTIONS: SDPS                                           
 _____________________________________________________________________
  TITLE:      OPS TRANSITION FAILURE MANIFESTATIONS                   
 _____________________________________________________________________
  DESCRIPTION:                                                        
  THE FOLLOWING MM ERRORS ARE DETECTED BEFORE I/O IS DISPATCHED AND   
  ARE THEREFORE REPORTED ONLY IN THE GPC'S DETECTING THE CONDITION.   
                                                                      
     1) MM SELECTED FOR IPL (UNLESS MASKED)                           
     2) MM FAILED OR POWERED DOWN                                     
     3) MM BUSY                                                       
     4) CHECKSUM BUFFER RESERVED                                      
                                                                      
  NOTE:  THE IPL SELECT DISCRETES ARE AUTOMATICALLY MASKED AT THE OPS 
         1 TRANSITION.  THEY MAY BE MASKED OR UNMASKED VIA ITEM 38    
         FROM SPEC 1.                                                 
                                                                      
  THE FIRST THREE CONDITIONS ARE BASED ON REDUNDANCY MANAGED          
  DISCRETES AND WILL BE REPORTED AS A SELF ERROR IN ALL GPC'S.        
  CONDITION FOUR CAN ONLY BE PRESENT IF PROCEDURAL RESTRICTIONS       
  ON MMU CONFLICTS AT OPS TRANSITIONS ARE VIOLATED.                   
                                                                      
  SYSTEM RESPONSE TO THE ABOVE CONDITIONS IS AS FOLLOWS:              
                                                                      
  A.  IF ANY OF CONDITIONS 1-3 IS PRESENT ON BOTH MMUS OR IF THE      
      CHECKSUM BUFFER IS RESERVED AT MMU PRE-POSITION, THE OPS        
      TRANSITION REQUEST WILL BE REJECTED DUE TO PRE-POSITION         
      FAILURE.                                                        
                                                                      
                  - CONTINUED ON SUPPLEMENT PAGE -                    
                                                                      
 _____________________________________________________________________
 CONCURRENCE:                           APPROVAL:                    
 LSIS:  HUGH D. STOVALL    DATE 11/21/95                             
      -------------------      ---------                             
 ASD:   ERIC C. BINGHAM    DATE 11/21/95                             
      -------------------      --------- DARRELL E. STAMPER 12/01/95 
 PF MGR: KAYLENE F. KINDT  DATE 12/01/95------------------- -------- 
        -----------------      --------- CHAIRMAN, SASCB      DATE   
 ____________________________________________________________________
 @






 +_____________________________________________________________________
                                                                      
                        SUPPLEMENTAL SHEET                            
                                                                      
 _____________________________________________________________________
  AUTHOR:                                          DR:              
  PAUL TICE              PASS PROGRAM NOTE               33268      
 ____________________                             __________________
  ORG/PHONE:          OPS NOTE ( )  USER NOTE (X)  DATE:  JUNE 1988 
  LSIS/282-7297            RELEASE NOTE ( )        REV C: 09/28/95  
 ___________________________________________________________________
  TITLE:                                                              
             OPS TRANSITION FAILURE MANIFESTATIONS                    
 _____________________________________________________________________
  DESCRIPTION: (CONTINUED)                                            
                                                                      
  B.  IF ANY OF CONDITIONS 1-3 IS PRESENT ON THE MMU SELECTED FOR     
      THE MAJOR FUNCTION OF THE OPS TRANSITION AND THE NON-SELECTED   
      MMU SUCESSFULLY PRE-POSITIONS, OVERLAY FAILURE WILL OCCUR ON    
      THE FIRST (SELECTED) MMU CAUSING A SWITCH TO THE SECOND MMU.    
      THE OVERLAY SHOULD THEN SUCCEED.  HOWEVER, IF THE OVERLAY THEN  
      FAILS IN THE GPC(S) DUE TO OTHER UNIVERSAL MMU I/O ERROR        
      CONDITIONS, THE GPC(S) WILL REMAIN IN CS OPS 000 OR IN AN       
      OPS 000 RS AS APPLICABLE.                                       
                                                                      
  C.  IF ANY OF CONDITIONS 1-3 IS PRESENT ON THE NON-SELECTED MMU,    
      BUT THE SELECTED MMU SUCCESSFULLY PRE-POSITIONS, THE OVERLAY    
      SHOULD SUCCEED.  HOWEVER, IF OTHER MM I/O ERRORS OCCUR ON THE   
      SELECTED MMU, THE SOFTWARE WILL SWITCH TO THE SECOND MMU AND    
      FAIL TO CS OPS 000 GPC(S) FOR BOTH SIMPLEX AND REDUNDANT        
      OVERLAY CASES (AS A RESULT OF "SELF ERRORS" FOR CONDITIONS      
      1-3).                                                           
                                                                      
      IN A 2 GPC RS, INDICATIONS OF THIS WILL BE FSP MESSAGES         
      INDICATING THE OTHER GPC HAS FAILED. CAM VOTES BY EACH GPC      
      AGAINST THE OTHER MAY OR MAY NOT BE PRESENT (REF: PASS USER     
      NOTE DR055300)                                                  
                                                                      
      IN A 3 OR 4 GPC RS, THE INDICATIONS OF THIS FAILURE WILL BE FSP 
      MESSAGES FROM EACH GPC AGAINST ITSELF AND FSP MESSAGES FROM     
      EACH GPC FAILING ALL OTHER RS GPCS.  CAM VOTES BY EACH GPC      
      AGAINST ITSELF MAY OR MAY NOT BE PRESENT (REF: PASS USER NOTE   
      DR055300)                                                       
                                                                      
      IF LDB POLLING WAS ENABLED PRIOR TO THE FAILED TRANSITIONS, AN  
      OPS 000 CS WILL RESULT IN DUAL LDB POLLERS, I.E. LDB POLLING ON 
      BOTH LDBS.                                                      
                                                                      
  IN ADDITION, FOR B AND C ABOVE:                                     
  IF A COMBINATION OF FAILURES RESULTS IN THE TARGET GPC(S) REMAINING 
  IN OPS 000 AFTER AN OPS TRANSITION HAS FAILED, SYSTEM SOFTWARE WILL 
  CONSIDER THE MAJOR FUNCTION ACTIVE IN THE TARGET GPC(S).  FOLLOWING 
  RESOLUTION OF THE PROBLEM(S) THAT CAUSED THE FAILED OPS TRANSITION, 
  THE MAJOR FUNCTION CAN BE RELOADED: IN THE ORIGINAL TARGET GPC(S),  
  OR IN ANY OTHER GPC(S) AFTER THE ORIGINAL TARGET GPC(S) ARE REMOVED 
  FROM THE COMMON SET.                                                
                  - CONTINUED ON SUPPLEMENT PAGE -                    
 _____________________________________________________________________
 @






 +_____________________________________________________________________
                                                                      
                        SUPPLEMENTAL SHEET                            
                                                                      
 _____________________________________________________________________
  AUTHOR:                                          DR:              
  PAUL TICE              PASS PROGRAM NOTE               33268      
 ____________________                             __________________
  ORG/PHONE:          OPS NOTE ( )  USER NOTE (X)  DATE:  JUNE 1988 
  LSIS/282-7297            RELEASE NOTE ( )        REV C: 09/28/95  
 ___________________________________________________________________
  TITLE:                                                              
             OPS TRANSITION FAILURE MANIFESTATIONS                    
 _____________________________________________________________________
 USER RESPONSE:                                                       
                                                                      
  TO MINIMIZE EXPOSURE TO THESE SITUATIONS, BOTH MMUS SHOULD BE       
  POWERED ON, NOT SELECTED FOR IPL, AND NO CONFLICTING MMU OPERATIONS 
  SHOULD OCCUR AT OPS TRANSITIONS.                                    
                                                                      
  ALSO REFER TO USER NOTES DRS 028364 AND 102936.                     
                                                                      
                                                                      
                                                                      
                                                                      
                                                                      
                                                                      
                                                                      
                                                                      
                                                                      
                                                                      
                                                                      
                                                                      
                                                                      
                                                                      
                                                                      
                                                                      
                                                                      
                                                                      
                                                                      
                                                                      
                                                                      
                                                                      
                                                                      
                                                                      
                                                                      
                                                                      
                                                                      
                                                                      
                                                                      
                                                                      
                                                                      
                                                                      
                                                                      
                                                                      
                                                                      
 _____________________________________________________________________
 @
