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Repair & Schematics
Dreamcast

Region Free BIOS (Dreamcast)

6min

In order to make the Dreamcast region free you require a new BIOS.

You can use

The best BIOS I find is called Japanese Cake. You can find the downloads on that site, or here. The new website is also here.

Here is the latest v1.032 BIOS from Japanese Cake.

jc-bootROM-v1.032.zip
īģŋ

Use the T48 programmer to program a blank BIOS chip if you have one, or just buy a Japanese Cake BIOS directly from us.

Choosing The BIOS

Start by powering on the Dreamcast and measuring the voltage on pin 23 (VCC) of the BIOS to confirm if you need the 3.3V or 5V BIOS.

Dreamcast BIOS Pinout
Dreamcast BIOS Pinout
īģŋ

The original BIOS for !RESET and !WE are disconnected, but on the new BIOS installs, these two pins need wiring up.

If your BIOS is 3.3V, you need this bios.

If your BIOS is 5V, you need this bios.

Installation

Before starting, use aluminium tape to cover the plastic connector so you do not melt it during work.

Hot air the old BIOS off, and solder the new BIOS in place.

Finally, join the !RESET (pin 1) to VCC (pin 23) so that the BIOS is not in reset.

Add one more wire, from !WE (pin 44, low for Write Enable) to B14 of the GD ROM connector (G1 !WRITE), so that if you want to re-flash the BIOS using DreamShell or similar you can.

Dreamcast BIOS Installed
Dreamcast BIOS Installed
īģŋ

Testing

In order to test the console, you will need the fan connected, and the GD ROM or GDEmu connected otherwise it will not boot.

If testing while open, make sure to prop up or hold the GD ROM / GDEmu up level so it is not bending downwards, as the connector between the motherboard and GD ROM is really poor and needs to be straight and level, otherwise nothing will boot.

Custom BIOS Options

If you have installed one of our BIOS chips, once started, go to Settings on the Dreamcast and press Start to open up the custom settings menu to change things like logo color, bypassing SEGA license and other options.

Dreamcast BIOS Settings
Dreamcast BIOS Settings
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Changing Region

Even if you change the BIOS to a region free BIOS, your Dreamcast will still be set to its original region.

This can cause issues with video output if say you install a region free BIOS into a Japanese console, and play UK games. The video will be off center, greyscale or flickering.

The region is saved in Flash Mask ROM, make sure to follow the Region Change guide to change the region.

Updated 01 May 2023
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TABLE OF CONTENTS
Choosing The BIOS
Installation
Testing
Custom BIOS Options
Changing Region
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