Sega CD import mod?

[SuperPsycho]

Hello,

I recently got ahold of the Japanese version of Sonic CD.  Apparently though I need either a special cartridge or I need to mod my Sega CD...   I tried to look up information on Google but the closest thing I found to what I was looking for was at this url:

http://www.digitpress.com/faq/genesis_import.txt

Near the bottom of this FAQ there was a short list of Sega CD import carts... one of which apparently didn't work with all games and one that wouldn't work with a 32x installed... well I'd like to have something that was effective and didn't require me to remove my 32X whenever I wanted to use it..... and then there was a note about a mod involving rewireing a couple resistors to make the Sega CD think it was a Japanese or American system, but there was no acctuall info on how to do this, nor a link to any other page about it.

I would really like to find out how to perform this modification on a model 1 Sega CD.  I was going to try e-mailing the author of this FAQ to ask about this but noting that the url listed at the top of the page for more recent updates to it was out of date and figured most likely the e-mail addresses would be as well.

[Agentspikey95]

this has been asked a million times, you need a bios swap.

or if you just wanna play the damn thing, go to http://gens.consolemul.com
and just download that and the bios files somewhere, set it all up, and pop the JAP sonic CD in your CD drive. but if you really wanna do this, your best bet would be to scour ebay for a jap Mega CD.

[Phraseblaster]

"SCDConv 2.5
This utility can convert most (not all) sega cd iso images to a different country code. i.e., if you have an US sega cd, but a japanese game, you can run this tool on it to convert the bootcode to US, so it will play on your sega cd without additional carts or modifications.
Usage: in a MS-DOS prompt, type "scdconv <isofilename>". It will tell you its current country code, and ask you which to change it to. It will also tell inform you if the probability of working is nil. After the file was converted, burn it to CD as usual."

source:
http://www.phantasy-star-universe.com/misc/

works great on my pal (m/s)egaCD

[Agentspikey95]

yeah, but not everyone has a CD burner.

[Endymion]

Looks as if the failure rate is high for Japanese games, including the one mentioned at the start of this thread.

[Computolio]

   Wow, I didn't know SCDConv sucks that badly. In my opinion, playing the Japanese version of Sonic CD on a US machine would be half the point of creating such a program.

   Someone with entirely too much time on their hands needs to make a BIOS switcher for the Sega CD that works like the old Amiga kickstart switchers- you hold down Reset until you hear the thing beep to switch BIOSes.

[NFG]

Making a BIOS switch on the front-loaders is easy, and in theory it's easy to make a dual-region cart for the top-loaders too.

[Guest_Madara]

I am in the same boat. The carts suck. SCDConv is a student project that bearly works and trying to find a Jap Mega CD is near impossible on Ebay. The only Mega CD players I can find are the Euro ver. that run off of that crappy PAL standard and 220 volts. I have all the sega bios images and I would like to do the switch as well. If anyone has info on this switch please let me know.

crgrindele@verizon.net

[SuperPsycho]

Making a BIOS switch on the front-loaders is easy, and in theory it's easy to make a dual-region cart for the top-loaders too.

So, would this mean I'd have to out and out replace the American BIOS with a Japanese SEGA CD BIOS?  Would it be possible to make it so I could use a toggle switch to switch between the two BIOS roms?

[NFG]

If you use an EPROM that's twice the size as the original you can burn one rom each in the lower and higher half of the memory, and use the MSB (most significant bit) pin as a select switch.  A truly simple mod if you've got an EPROM burner, a bit of a PITA if you don't.  =)

[SuperPsycho]

If you use an EPROM that's twice the size as the original you can burn one rom each in the lower and higher half of the memory, and use the MSB (most significant bit) pin as a select switch.  A truly simple mod if you've got an EPROM burner, a bit of a PITA if you don't.  =)

I don't suppose it'd be possible I could pick up a cheap used eprom burner for... oh say.. An Apple II... and do this with my IIgs?  And I'd be able to use same BIOS files that are currently up for download for emulator use?  So this larger eprom would have the same number of pins and I'd have a switch on one of them that would change which part it accesses?

[note: if I'm coming off as a clueless airhead here, it's likley that it what I am]

[ido8bit]

I only tried SCDconv once.  A friend without a converter cart desperately wanted Soulstar, but could only find the US version.  The SCDconv patched version did boot, but crashed after a couple of levels from memory.

I use a Datel CDX pro, I haven't had any problems with it other than it won't work with a 32X at all.  You can't play 32X CD games, and regular MegaCD games won't work either.   There are several versions though.  From memory v1.0 and v1.7 only work on a MegaCD 1 (front loader).  If you have a top loader you must get v1.8 or v2.0.  As for game compatibilty I don't have anything that doens't run on the v1.8/v2.0 carts, I haven't checked everything on the earlier carts.

Somewhere on my HD I have the schematics and software for an EPROM burner.  Maybe when I find the BIOS image files I'll get motivated to build it and attempt a US/JAP/EUR switchable MegaCD.  

Was there a JAP version of the MegaCD 2?  I've only got 1 precious MegaCD and I don't want to risk killing it.  I do have a crapload of MegaCD 2 that I've got no problem messing with....

[hellbelly]

Has anybody tried this out?

I've just bought one, just waiting to get my hands on a megacd now.

Pete

[Agentspikey95]

and 220 volts.

HELLO
this is why the system runs on like 9vDC. so you can use all kinds of adaptors.
And from what i've heard the power inputs are all the same connector, all the same voltage, and all the same everything else, correct me if i'm wrong

[fragment]

Wow that is alot of  work to play an import. Evertime that i have tried SCDconv it has worked. I have applied it to PAL and JAP games and no problems whatsoever. That includes Sonic CD Jap. What games is everyone having a problem with? And everyone doesn't have a CD Burner these days? That was like five years ago. Now it is not everyone has a DVD burner....but soon I won't be a part of that crowd.

Has anybody tried this out?

I've just bought one, just waiting to get my hands on a megacd now.

Pete

[ido8bit]

I tried it on US version of Soulstar, so it could be played on a PAL MegaCD 2.  The converted version booted, but crashed ~3 levels into the game...   The original US version played fine on a PAL MegaCD with a CDX pro converter cartridge.

How much is the patched BIOS?  Would be much quicker than building a JAP/US/PAL ROM switcher, but I'd still rather use the original ROM images incase there are compatibility problems with the patched version.

[hellbelly]

How much is the patched BIOS?  Would be much quicker than building a JAP/US/PAL ROM switcher, but I'd still rather use the original ROM images incase there are compatibility problems with the patched version.

It cost me 25 euros plus shipping (which was 3 euros to the UK).

Cheers
Pete

[Endymion]

Wow that is alot of  work to play an import.

And burning a CD of every game you want to play isn't effort? And storing and keeping up with a damn copy in addition to your original? That's a pretty sucky solution I'd say, and the site offering it for download admits it isn't perfect. If that's not good enough for you we have peeps right here telling us about their problematic experiences.

Where would one buy the BIOS chip to mod? I don't see a link to anything there.

[hellbelly]

Sorry - I forgot about that, I couldn't see any info about buying it either.  I just emailed him and asked if he was still selling them.

Pete

[Agentspikey95]

Here's an idea, once you have an eeprom writer, download the bois reigon of your choice(looks purposes only) open it up in a windows rom header editor,  and change the reigon code to JUE. worked for me in Gens. Or if you want, i'll email you a pre-modded bios ROM, and all you'll hafta do is burn it to an EEPROM and shove it in there.

[Rockin' Kat]

I hope you don't mind my bumping this two year-old topic... :unsure: I just wanted to say that I ended up buying that multibios and had someone install it. It came in from Germany and works great.

In addition... the person who did the installation added a 50/60Htz switch to the genesis... and also made it so that stereo audio mixed between the model 1 Genesis and model 1 Sega CD over the expantion port..so no cheezy patch cable setup.    

[blackevilweredragon]

I hope you don't mind my bumping this two year-old topic... :unsure: I just wanted to say that I ended up buying that multibios and had someone install it. It came in from Germany and works great.

In addition... the person who did the installation added a 50/60Htz switch to the genesis... and also made it so that stereo audio mixed between the model 1 Genesis and model 1 Sega CD over the expantion port..so no cheezy patch cable setup.  

i don't understand the patch cable really..

my Genesis 1 expansion port unmodified, can take in a stereo signal, and using my Sega CD 2 on it, through the headphone connector I get full stereo sound...

because of that, I modified my Genesis 1 with a mini 9-pin DIN connector, and grabbed the stereo audio from the solder points on the headphone jack..

works great

[NFG]

The Gen1 doesn't have stereo inputs on the expansion port, it really doesn't.  If yours does it's special.  =)

[blackevilweredragon]

The Gen1 doesn't have stereo inputs on the expansion port, it really doesn't.  If yours does it's special.  =)

then mines special..  cause mine really does...

mine does NOT say High Definition Graphics, just says Genesis, and 16-BIT, and has the Produced By or Licensed By screen..  if that helps

i KNOW it's got Stereo input on it's expansion port, because I have a test CD that tests stereo channels..  and sure enough, left is left, and right is right..

Incase you want to see it, this is my setup:  http://blackevilweredragon.spymac.com/segacd1.jpg

Oh, and anyway you want me to prove it, I will...  (cause you know I would  )

[GZeus]

http://www.genny4ever.net/megacart/megacart_v1.html
I can hardly wait.

[arfgh]

"The Gen1 doesn't have stereo inputs on the expansion port, it really doesn't.  If yours does it's special.  =) "

and the genesis 2 yes ? So the expansion port of the genesis get all the sound that is generated by the mega cd ?
And can't we do the same with some mod on the genesis 1 ?