11/26/2021

Dreamcast Boot Bin

Dreamcast boot bin download
  1. Sega Dreamcast Dc_boot.bin
  2. Dreamcast Boot Bin
  3. Download Dreamcast Dc Boot Bin

You may also like these Sega Dreamcast ISOs. Jojo's Bizarre Adventure: Soul Calibur: Marvel vs. Capcom 2: Phantasy Star Online v1: Sonic Adventure: Sonic Adventure 2: Resident Evil 3 - Nemesis: Resident Evil Code - Veronica Disc 1. In addition you should have the BOOT.BIN (generally called 1STREAD.BIN) and IP.BIN in this directory. Run the program BINHACK.EXE. When it prompts you for the Binary file to modify, Pick the BOOT.BIN. If it detects that the BOOT.BIN is a Windows CE Exectuable (0WINCEOS.BIN), It will not modify the 0WINCEOS.BIN.

  • 3File Format

About

A MR image is an image format solely used inside an IP.BIN file to show off a logo during the boot screen process of the Sega Dreamcast.

Games powered by Windows CE boot screen

This image format was used in commercialized Dreamcast games utilizing Windows CE SDK where we see a 'Powered by Microsoft Windows CE' logo. It is now commonly used in homebrew to distinguish the creator(s) of the application or to disassociate the application being produced by or under license from Sega. The MR image must be inserted into a IP.BIN file at offset 0x3820 in order to be viewed during boot sequence. Since IP.BIN is restricted to a 32k file size, there are a couple of guidelines the MR image must meet to in order to fit inside the IP.BIN.


MR Image must be:

  • 320x90 or less
  • Max 128 colors
  • Less than 8192 bytes to fit in a IP.BIN
  • The transparent color is #c0c0c0, or 192, 192, 192 in RGB


Tools

Selfboot-Inducer

SiZious's Windows Tool to create homebrew compilations. Using this application you can view and create MR images from other various other image formats.


MR GIMP Plugin

Bin

GIMP is a cross-platform image editor available for GNU/Linux, OS X, Windows.

Using this GIMP plugin('file-mr.py'), you can create view, edit, and create a MR image from any other image format that GIMP supports.

File Format

The file format is composed of three sections: Header, Palette, and the Image Data. All of the data written in the file is in little-endian format.

A MR file starts off with a 30 byte header.

Dreamcast Boot Bin

File Header

Size (bytes)Contents
2'MR'
4Total file size
4Crap (fill with 0's)
4Image data offset in bytes (Header size + Palette size)
4Image width
4Image height
4Crap (fill with 0's)
4Amount of colors in palette

Palette

The header is followed by the image's palette. The palette is composed of palette entries where each palette entry is 4 bytes long and is stored as BGRA. The alpha byte goes unused. The maximum number of palette entries is 128.

Sega Dreamcast Dc_boot.bin

Palette Entry
BGRA

Dreamcast Boot Bin

In total, the byte size of your palette should be number of colors * 4.

Image Data

Download Dreamcast Dc Boot Bin

Lastly, the image data. The image data is basically an array of indices, each a byte long, that refers to a palette entry in the palette. The image data is compressed using a form of Run-Length Encoding (RLE). The python algorithms to encode/decode the image data are shown below.

Encoding Algorithm

Decoding Algorithm

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