H091381 - 9595A/8641 RAID ARRAY SYSTEMS WITH SCSI TAPE OR CD-ROMS              
                                                                                
 TEXT:                                                                          
 RAID Array systems, which have an optional CD-ROM or tape                      
 drive connected to the RAID controller adapter, may experience                 
 difficult to diagnose configuration problems if the device                     
 address is not set correctly, terminators are installed, or if                 
 other option jumpers are set incorrectly (9595A & 8641 systems).               
                                                                                
 The supported optional tape drive is shipped preset as SCSI                    
 address 5.  The optional CD-ROM is usually set to address 6.                   
 Use the preset address, or 4 thru 6,  to avoid conflicts                       
 with addresses 0 through 3, which are reserved by the                          
 adapter firmware (RAID Controller Diskette) for fixed                          
 disks in the RAID array.                                                       
                                                                                
 There should be NO TERMINATORS on these devices when                           
 installed in these systems.  Termination is preset by                          
 the DASD fixed disk support structure.                                         
                                                                                
 Note:                                                                          
 This restriction does not apply to devices attached to any                     
 other optional SCSI adapter, which may be installed in                         
 the system.                                                                    
                                                                                
 The only tape option supported on the RAID array controller                    
 used in the 9595A is:                                                          
                                                                                
 IBM 4/10GB 4MM DAT TAPE DRIVE OPTION kit, Feature code 7499,                   
 option number 74G8632.  (Note: the option number was originally                
 8191339 and was recently changed to 74G8632.)                                  
                                                                                
 The FRU is P/N16G8456, which supplies only the tape drive.                     
                                                                                
 Note:                                                                          
 There are currently two different tape drives which may be                     
 disbursed under FRU P/N16G8456.  They are interchangeable, but                 
 have different addressing methods, as follows:                                 
                                                                                
     Rear View of 4MM SCSI Tape Drive                                           
     (Addressed by switches on the drive)                                       
                                                                                
  _________________________________________  SCSI ID= 4 | 5 | 6                 
  | ____________________________          |  -----------|---|----               
  | |     SCSI Connector       |    ___   |  sw 1     X | O | X                 
  | |__________________________|   |ooo|  |  sw 2     X | X | O                 
  | <terminator>                   |ooo|  |  sw 3     O | O | O                 
  | <terminator>                          |  X= off                             
  | ______   oo           _______________ |  O= on                              
  | |oooo|   |            |8<--->4|3|2|1|<---address and                        
  | ------   |            |_______|_|_|_| |  configuration                      
  |_Power____|____________________________|  switches                           
             |                                                                  
             No jumpers should               Switches 4 thru 8                  
             be installed here               Must be off.                       
             (JMP3 & JMP4)                                                      
                                                                                
 * Note: 01291500 errors may be caused by jumpers in positions                  
   JMP3 and JMP4 on 9595A RAID ARRAY systems.                                   
                                                                                
  *****************IMPORTANT NOTE********************************               
  Note: SCSI Bus Adapter FRU P/N92F0324.                                        
                                                                                
  A SCSI bus adapter is required between the WIDE SCSI cable and                
  NARROW SCSI devices, such as the CD-ROM or the 4mm optional                   
  tape drive.  CARE MUST BE EXERCISED WHEN THIS ADAPTER                         
  IS INSERTED INTO THE REAR OF THE TAPE UNIT TO PREVENT MIS-                    
  PLUGGING.  The adapter is keyed, however some tape drives                     
  have connectors that do not have the corresponding keyway. This               
  allows the adapter to be mis-plugged one pin position, either                 
  direction.                                                                    
                                                                                
  Mis-plugging one direction has been known to cause the                        
  systems to shut down (power supply self-protect). When this                   
  condition is corrected the system power supply will operate                   
  normally.  (Power supply self-protect is explained on page 290                
  of the PS/2 Hardware Maintenance Manual S52G-9971-01, dated                   
  Sept, 1993.)                                                                  
                                                                                
  Mis-plugging in the other direction has been know to cause                    
  the device to be unrecognized (configuration failures).                       
  +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++               
     Rear View of Later version of 4MM SCSI DAT Tape Drive                      
     (Addressed by jumpers on the drive)                                        
                                                                                
  _________________________________________  SCSI ID| Pins jump'd               
  |                                       |  -------|------------               
  |                   ID and Option jumpers     4   | 5&6 |                     
  |                   ___________         |     5   | 5&6 |1&2                  
  |                 15|..... ...|1        |     6   | 5&6 |3&4                  
  |                 16|.........|2        |                                     
  | =============  ===============  ____  |                                     
  | | SCSI Signal Cable Connector| |oooo|<--Power                               
  | ============================== ------ | connnector                          
  |_______________________________________|                                     
                                                                                
         Feature             |   Pins jumpered                                  
  ---------------------------|-----------------                                 
  Terminator power on        |   15 & 16                                        
  N/A                        |   13 & 14                                        
  Active terminator enabled  |   11 & 12                                        
  Data Compression enabled   |    9 & 10  (Off, unless clearly                  
                                          required)                             
 A feature jumpering information label is on the on the unit.                   
 Jan. 18, 1996