External Format

The bank consists of a header followed by one or more Run records.

The header includes:-

1. A version number. This will be important if the DAMN database file is ever reissued. The required version number is stored in the TDMM titles bank and is used to confirm that the local site has got the correct version.

2. Compression algorithm. This will be used if we employ compression above and beyond that listed above.

3. A format number. This is used to differentiate single sub-run DAMN banks (format 1) from multiple sub-run DAMN banks and all DARN banks (format 0)

4. Sub-run number. For format 1 this holds the sub-run number. For format 0 it is always 0.

A Run record consists of:-

1. A 3-word Run record header:-

    +1  -ve. run number (the minus sign flags a new run record)
    +2  Default Applied Mask
    +3  Default Result mask
   

2. One or more Run record entries. The layout of each entry is:-

    +1 entry_mask*10**8 + GTID    
   
     where  entry_mask = 0 GTID only
                       = 1 GTID + Applied Mask
                       = 2 GTID + Result Mask
                       = 3 GTID + Applied Mask + Result Mask.
    +2 Applied Mask if necessary
    +3 Result Mask if necessary