The IDX is an index for a DAT archive file.
The first 4 bytes in IDX file is the number of items described in the IDX file. Then all the items are listed. Each item is 28 bytes.
|16 bytes||Name of dataset|
|4 bytes||Offset to data in DAT file|
|6 bytes||Unknown (always 0 = hex 00 00 00 00)|
|2 bytes||Type ID (see LST File Format)|
The DAT file is a simple continuous file of data. Each item starts with a 2 bytes Type ID, repeating the same Type ID defined for the item entry in IDX file. The rest works as it does in an LST file.