Sega CD Multi Bios (HOW)

[immortal001]

Hi All,

Was wondering if anyone could assist with this. I have been looking at the multi- bios mod perfomed by arakon on The Tavern... I have tried to arange to buy the mod but I don't use paypal (bad mojo) and thats all thats accepted.

I have read details on how to make the multi bios (Combine original bios and other bioses on one chip with selection switches to trigger each bios) but would not have a clue where to start - I know how to combine them, have a eeprom writer (or access anyway) that will do the chip.. Can anyone help in the order of joining the bioses or any other info which may help.

The reason I'm looking for this mod is I have 3 CD systems (Mega CD EUR 1, Sega CD US 2, MEGA CD JAP 1) and am sick of having them all here just to play the different games on harware. I know I can repatch and burn them to cdr but would prefer the bios mod do to bein to lazy to burn some more copies.

Pls help out with any info on performing this mod... I can;t seem to find much anywhere (except for the old posts on The Tavern where arakon discusses building it)

Cheers

Immortal001

 

[ExCyber]

First of all, you need to either patch out the territory protection in each BIOS image (I might be able to find time to do this if you don't know anyone who knows how to do it; PM me if needed) or fit territory/refresh switches to your MD, otherwise the foreign BIOS images will not run on your MD. Then it's a matter of throwing them into a suitably-sized EPROM (8MBit / 512Kx16 is good, you can fill the fourth section with a small game or demo if you like) and wiring the switches. The order doesn't really matter, that will only affect the correspondence of switch position to BIOS image. Basically then you just wire the switches as per Arakon's install instructions, adjusting for any variation in your ROM's pinout (though it will likely be the same).

 

[timofonic]

I was send a message to you, Ex-Cyber, i waiting your response about eliminate the country check of SegaCD/MegaCD bios...

Kind regards,

timofonic