DGT data format

■File layout

offset	size	function
$000	$100	header
$100	$20	directory
$120	variable	CLUT (color lookup table)
Indeterminate	variable	bitmap data

◆Header

offset	size	Explanation
$00	word	Header size = $100
$07	Part-Time Job	Number of directory entries = $01
$08	long	File size excluding header
$10	$10	Identifier = "DIGITIZER_3_Ver2" ("_" is a space = $20)
$20	$E0	Dummy data, all $00

◆Directory

offset	size	Explanation
$00	long	Directory size = $20+CLUT size (variable)
$04	word	Horizontal display position (usually $0000)
$06	word	Vertical display position (usually $0000)
$08	word	Horizontal image size
$0A	word	Vertical image size
$10	$10	Dummy data (all $00)

●The free address for "Directory Name" is $20.

●All empty addresses except for "directory name" are $00.

◆CLUT

Exists in palette mode and run length mode.

offset	size	function
$00	Long x number of pallets	CLUT data

●One palette consists of "long x 16 colors".

●If even one color is used, data for one palette will be reserved.

CLUT data

MSB　
│ │       Palette number　
┌─┼─┬─┬─┬─┬─┬─┬─┬─┬─┬─┬─┬─┬─┬─┬─┐
│*│E│D│C│B│A│9│8│7│6│5│4│3│2│1│0│
└─┴─┴─┴─┴─┴─┴─┴─┴─┴─┴─┴─┴─┴─┴─┴─┘

│        Color data           LSB
│ │B│G│R│   B   │   G   │   R   │
┌─┬─┬─┬─┬─┬─┬─┬─┬─┬─┬─┬─┬─┬─┬─┬─┐
│*│0│0│0│4│3│2│1│4│3│2│1│4│3│2│1│
└─┴─┴─┴─┴─┴─┴─┴─┴─┴─┴─┴─┴─┴─┴─┴─┘
*=Not used

●For palette numbers that are not used in bitmap data even if there is a CLUT, the color code will be $FFFF. This allows you to know the unused pallet numbers from the CLUT.

◆Bitmap data

offset	size	function
From $00	Word x image size	Palette number for each pixel

★ Graphic Tools Guide ★ Format list