5. NULL VOLUME FILE FORMAT DEFINITION

TABLE 6.1 NULL VOLUME DESCRIPTOR RECORD

FIELD  BYTES    FORMAT  DESCRIPTION                                           CONTENT             
                                       
 1     1-4      B4      Record sequence number                                    (1)                 
 2     5        Bl      1-st record subtype code                                (192)               
 3     6        Bl      Record type code                                        (192)               
 4     7        Bl      2-nd subtype code                                        (63)                
 5     8        Bl      3-rd subtype code                                        (18)                
 6     9-12     B4      Length of this record                                   (360)               
 7     13-14    A2      ASCII/EBCDIC flag                                          A$                  
 8     15-16    A2      blanks                                                     $$                  
 9     17-28    A12     format control document                          CCB-CCT-0002        
10     29-30    A2      Superstructure format control document                     $E
11     31-32    A2      Superstructure record  format revision                     $A 
12     33-44    A12     Logical volume  generating  facility software        <......>
                        release and revision level                         
13     45-60    A16     ID of physical volume containing this volume         <......>
                        descriptor           
14     61-76    A16     Logical volume identifier                            <......>            
15     77-92    A16     Volume set identifier                                <......>            
16     93-94    I2      Total number of physical volumes in the logical vo1ume     $1                  
17     95-96    I2      Physical volume sequence number of the first               $1
                        tape within the logical volume                             
18     97-98    I2      Physical volume sequence number of the last                $1
                        tape within the logical vo1ume                             
19     99-100   I2      Physical volume sequence number of the current             $1
                        tape within the logical vo1ume                         
20     101-101  I4      First referenced file number  in this physical           $$$1
                        volume whithin the logical volume.                                        
21     105-108  I4      Logical volume within a volume set                       $$$2 
22     109-112  I4      Logical volume number within physical volume             $$$2 
23     113-120  A8      Logical volume creation date (YYYYMMDD)              <......>            
24     121-128  A8      Logical volume creation time                         <......> 
                        (hhmmssdd, dd=deci-seconds)                   
25     129-140  A12     Logical volume generation country                    <......>           
26     141-148  A8      Logical volume generating agency                     $$$$$$$$          
27     149-160  A12     Logical volume generating facility                   <......>            
28     161-164  I4      Number of file pointer records in volume directory       $$$0                
29     165-168  I4      Number of records in volume directory                    $$$1                
30     169-260  A92     Volume descriptor spare segment (always blank filled) <$....$>            
31     261-360  AlOO    Local use segment                                     <$....$>