Out of sheer curiousity, after making a tidy Super Mario RPG cartridge, I wanted to try a Star Ocean English cart. Using the same 29L3211 EEPROM, an original copy of the Japanese Super Famicom Star Ocean Cart and a SMD Voltage Regulator.
It looks like this method could have trouble on later revision SNES consoles, here’s a post by MrPete1985 which explains the issue, and an alternative method :-)
Most of this is identical to the Super Mario RPG mod. The Star Ocean cart has two maskroms on it, the English translation only alters info in the first maskrom, so you only need to remove that chip, I used the pin method to remove the existing chip – U1 P0 MASKROM.
Now take your programmed 29L3211 and bend up legs 1, 23 and 33 – we need to feed these legs 3.3v but the board will give them 5v.
I soldered the chip in place (much like I soldered the Saturn Region Free BIOS), I’ve also added some solder onto those lifted legs, ready to wire them up (I forgot to photograph this!)
For the Voltage Regulator, you need to feed it 5v and Ground, there’s a very convenient spot nearby the EEPROM so use that. I’ve also cut off the middle leg and straightened the tab out so that they don’t touch the cart board (although that’s probaby overkill on my part), the tab is also 3.3v output.
I had to use a 100nf Capacitor on the Voltage Regulator to get the 29L3211 to work with it. My first 29L3211 had a bad ROM on it, and when I removed it to replace with a newly programmed one from Bad_Ad84 (cheers again!) I managed to lift one of the contact pads, hence the extra yellow wire in my photos. The purple wire is the 3.3v for the chip.
I had to bend the 100nf Capacitor over so that the cart would fit in the plastic shell.
Check out my Super Mario RPG guide for more info on soldering this together, and about the Voltage Regulator and why I’ve added that 100nf Capacitor. Also, this is how I fitted a new battery to the cart.
I downloaded an already translated ROM file, which had the DeJap English Patch already applied. I can’t link to it here, or offer it for download, but it was easy to find and download “Star Ocean (Japan) [En by DeJap v1.0].zip”
Splitting the ROM
The ROM file is 6,291,456 bytes, which is the complete ROM – both of the MASKROM chips, we are working with just the first MASKROM, so we need to split the file. It’s possible to do this using a Hex Editor, I used a freebie binary file splitter though as it was easier…
This will give you two files, we want the first one which should be 4,194,304 bytes in size.
Like I said earlier, the first time I made this cart it didn’t work. I don’t know if it was because there was a problem with my ROM file, or because the 29L3211 had been badly programmed. I had a look at the readme for the DeJap translation and it mentions it breaks the ROMs checksum, so I decided to focus on this.
I used uCON64 to check the original (BEFORE splitting) ROM file. I downloaded and configured the GUI for uCON64 to make life simpler.
Clicking on Show info and choosing the ROM file it tells you all about the ROM file, including confirming that the Checksum was bad…
So, back to the SNES tab of uCON64 and click on Fix checksum….
Then I checked the newly created ROM, using Show info again, now displaying a good checksum.
Now I split the file again, exactly the same way as before, and sent the file and chip to Bad_Ad84. This time, it worked on my cart. I still don’t know if it was an error in the ROM file, or badly programmed the first time I tried this mod, but I now I have a working cart.