The Sega Mega CD Region Free BIOS is a direct swap for the region locked BIOS chip inside a Sega Mega CD. It allows the Mega CD to dock with any region of Mega Drive and it bypasses the region protection of imported games.
You must select your exact Mega CD model number from the options. Mega CD BIOS files are model specific. You can however choose any Boot Animation region.
Single Region Mega CD BIOS
From the Boot Animation option you can select which region you would like your region free BIOS to be. You do not have to stick to your console’s region. For instance if you have a PAL Mega CD but prefer the North American BIOS animation and sound, you can select this and install it no problem.
The Japanese BIOS has a little more compatibility than the European and North American ones but the downside is that the battery backup menu and CD player are both in Japanese.
All the single region BIOS chips require the removal of the original region locked BIOS, installing a socket, and fitting the new region free BIOS into the socket. On very early Mega CD units, there may be a BIOS socket already installed which means replacing the BIOS is very straight forward.
Mega CD MultiBIOS 3-in-1 Chip
If you select the MultiBIOS option from the Boot Animation selection you will receive one chip that contains all three BIOS regions. These regions can then be loaded with a switchless region mod installed inside the Mega Drive.
This chip requires de-soldering the old BIOS chip, installing a socket, and fitting this BIOS into the socket, leaving out pins 38 and 39. Pins 38 and 39 will need wiring to the expansion port. The Mega Drive switchless region mod will need wiring to corresponding expansion port pins on the Mega Drive.
When correctly installed the Mega CD BIOS version will match the Mega Drive region. If you select European region on the Mega Drive the European Mega CD BIOS will load. USA region, USA BIOS, etc., including all the different BIOS screen animations and music. All BIOS files are also region free meaning it really doesn’t matter which you load but this mod will allow those few tricky games which require a specific BIOS to be playable. It is 100% region free.
This MultiBIOS uses a universal BIOS order meaning it doesn’t matter which Mega Drive switchless mod you have installed. As long as it is wired correctly for your switchless mod, the BIOS and console region will match.
*This mod requires that you have a switchless region mod installed into your Mega Drive. The switchless mod will need two signals wiring to the expansion port of the Mega Drive in order to select the BIOS that will load.
**Do not buy MultiBIOS if you only intend to use it as a standard BIOS replacement chip. Please select one of the single regions from the Boot Animation option.