Game File Hacking

Ultima V (PC)

.TLK Files

Ultima V has .TLK files but only four of them:

  • CASTLE.TLK
  • DWELLING.TLK
  • KEEP.TLK
  • TOWNE.TLK

In Ultima IV, the files were all 4608 bytes made up of 288 bytes for each of 16 characters.

Here in Ultima V, they are variable length and a hexdump of the files reveals no readable text.

Castle, Dwelling, Keep, Towne

As well as .TLK, each of Castle, Dwelling, Keep, Towne has a .DAT file and a .NPC file. There are quite a few additional .DAT files but these are the only four .NPC and .TLK files.

.DAT Files

Looking at a hexdump of CASTLE.DAT, it's clearly a map (likely referring to tiles either with one byte or two). The Castle, Dwelling, Keep, Towne .DAT files are all 16384 bytes. I suspect BRIT.DAT is the surface of Britannia and UNDER.DAT is the Underworld. I'll attempt to tackle Castle, Dwelling, Keep and Towne first, though.

TILES. Files

There are two TILES. files:

  • TILES.4
  • TILES.16

which I presume are the tiles at different bit-depths. There are actually a lot of files with a .4 and .16 pair.

The first four bytes of TILES.4 are little-endian 0x8000 = 32768 and the first four bytes of TILES.16 are little-endian 0x10000 = 65536.

Assuming 512 16x16 tiles these look the exact data lengths we'd expect.