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                           IBM ECA
              Engineering Change Announcement

Parts removed from this machine and returned to IBM must be genuine,
                      unaltered IBM Parts

         IBM World Trade Corporation, CE Department Germany
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 EC NUMBER         :  ECD22611     DATE             : 93-06-17
 MANDATORY         :  N
 AUTOMATIC SHIPMENT:  N            SERVICE CODE     : 33
 PARTS SOURCE      :  YASU         AVAILABILITY DATE: 93/05
                                                                                
 PURPOSE:                                                                       

 To solve hung-up problems which may occur when the Bus Master                  
 Adapter is installed in the PS/55 Model 5551-Tx9 Stage 1,and                   
 this field EC was revised from EC# C27278 FBM# 64F8691.                        
                                                                                
 The following adapters have Bus Master Function.                               
 -Micro Channel SCSI Adapter/A (16Bit,32Bit)                                    
 -Inteligent Communication Adapter/A Portmaster                                 
 -Numeric Processing Adapter                                                    
 -Japanese Voice Adapter/A                                                      
 -80MB HDD attached SCSI Adapter/A                                              
 -Token Ring 16/4 Bus-master 32 Adapter/A                                       
                                                                                

 Type             Machines Affected                             
 Mod.  With       and/or Feature/Device    B/M to be  Serv Syst 
 Stg.  B/M        Description              Installed  Hour Hour 

 Plant 98                                                       

 5551- B/M0005551 S/N RANGE                B/M64F8691 00.5 00.5 
   T09               9740001-->9744700                          

                                                                                
 PHYSICAL CHECK:                                                                

 Check the System Board P/N.                                                    
 When the Bus Master Adapter is installed in the 5551-T09 Stage
 1 if the System Board is P/N 65X1377 or 94X1572, install this
 FBM.
                                                                                
 PREREQUISITES: NONE                                                            
                                                                                
 COMPANION: NONE                                                                
                                                                                
 CONCURRENT: NONE                                                               
                                                                                
 DETAIL:                                                                        

 Replace the  System Board with P/N 56F7421.                                    
                                                                                
 NOTES:                                                                         

 Return the removed System Board with EC completion report                      
 to stock center as soon as possible after EC installation.                     
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