Ultima VI Internal Formats

This page deals with the details on the specifications of the file formats for the different files included in Ultima VI.

LZW Compressed Data
Some files or blocks inside files are LZW compressed. LZW compressed data has the following format:

Libraries
Libraries are contain several items of the same type, inside the same file. Libraries have the following structure:

For simplicity, the following names are used for specific types of library files:
 * s_lib_16: a library file which does contain the File Size part, and where each offset in the Index part is 2 bytes (16 bits) long.
 * s_lib_32: a library file which does contain the File Size part, and where each offset in the Index part is 4 bytes (32 bits) long.
 * lib_16: a library file which does not contain the File Size part, and where each offset in the Index part is 2 bytes (16 bits) long.
 * lib_32: a library file which does not contain the File Size part, and where each offset in the Index part is 4 bytes (32 bits) long.