Simcity 2000 Special Edition DAT IDX

• Return to the list of games

Choose archive extension:

IDX + DAT

• Format Type : Archive
  
• Endian Order : Little Endian
  

Format Specifications

// for each file


uint32 {4}   - ID

uint32 {4}   - File Offset




MultiEx BMS Script

Not written yet

Notes and Comments

• The *.idx file contains the directory, the *.dat file contains the file data

Compatible Programs

• Game Extractor
  

SC2

• Format Type: Interchange File Format (IFF)
• Endian Order: Big Endian

Format Specifications

// HEADER

char {4}	- Chunk Type ID ('FORM')
int32 {4}	- Total count of bytes in file minus first 8 in the header
char {4}	- File type (always 'SCDH' for SimCity 2000)

// Begin segments/nested chunks. For each nested chunk:

// Segment header

char {4}	- Segment type
int32 {4}	- Byte count of this segment minus this header (-8 bytes)

// Segment data, begin sub-segment bytes (let x = the byte's value)

byte {1}

// If 1 <= x <= 127:

byte {x} - Raw, uncompressed data

// If 129 <= x <= 255:

byte {1} - This byte repeats x times.

// Repeat for the rest of this segment's data length.

Notes and Comments

• This is the file format in which cities are stored. See the IFF page on Wikipedia (linked above) for more information on the format, although it is essentially a generic container file format.
• All of this information is thanks to the research done by David Moews, with a document here.
• After the header, the rest of the file is made up of chunks containing an 8 byte header followed by its data. Almost all segment data is compressed using a run-length algorithm. Specifically:
  • The compressed data is a series of two kinds of chunks
  • In the first kind, the first byte equates to an integer 1 to 127. This means the byte is counting how many data bytes follow.
  • In the second kind, the first byte equates to an integer 129 to 255. If you subtract 127 from it, you end up with a count of how many times the following byte is repeated.
  • Chunks with a first byte of 0 or 128 never seem to occur.
  • Therefor, the maximum size of an uncompressed sub-chunk can be 127 bytes.

Segment Types

• The following table is a list of segment types in the order they typically appear. Unless noted, they are compressed using the above algorithm. The lengths given are their uncompressed lengths.

Seg. type	Length (bytes)
CNAM	32 (Uncompressed)
MISC	4800
ALTM	32768 (Uncompressed)
XTER	16384
XBLD	16384
XZON	16384
XUND	16384
XTXT	16384
XLAB	6400
XMIC	1200
XTHG	480
XBIT	16384
XTRF	4096
XPLT	4096
XVAL	4096
XCRM	4096
XPLC	1024
XFIR	1024
XPOP	1024
XROG	1024
XGRP	3328

Additional notes on segment types:

CNAM	The name of the city, uncompressed, and also optional it seems. When it's present, the length byte is a number 0 to 31, with that many bytes of city name. It's padded to 32 bytes with zeroes.