Mega-CD real region free on game discs

Hi, first, sorry for my english, This work is AWESOME... Im so exited, recently I fix mi Sega CD Model 2 USA, Change the Fuse and replace the Lens.. woks perfectly ^^ .. now I can try this multi bios, can anyone explainme or make a nob guide for my step by step? If anyone speaking spanish would be grat... Thanks and Incredible work...
Emiliano from Argentina...

 

Region free BIOS is simple an BIOS replacement which loads ANY MD disc, regardless of region. You simply put it in and forget about it. :thumbsup:

 

Hi l_oliveira... I understand that, but where I can find the Bios? or how can I make it?

 

You can order from one of the forum members who provide this service or write one to a EPROM chip yourself:

- Download modified BIOS on first post of this thread.
- Byteswap it with the provided tool. (Non byteswap file is suitable for emulator but not for the real machine)

- Write the EPROM with the BIOS data.
- Install it on your MEGA-CD (Replace the original with the new chip)

- Enjoy region free gaming ! :thumbsup:

 

OK ... who members can sell me 2 or 3 of this EPROM?

 

"Will Mod for Food":
http://www.assemblergames.com/forums/member.php?u=63433

With him, you can't go wrong. :thumbsup:

 

Thanks l_oliveira... i already contact with him... now when the EPROM arrives I soldering the EPROM and that is all? In that case, what bios show me my sega cd model 2 usa?

 

i just installed the regionfree bios ( the patched pal version ) on my eu megacd2 and its working great with us games but none of my jap games work.

for example heavy nova is working past the sega loading screen but then hangs you can see "now loading" is blinking but nothing happens

but the music is played

you can try it with gens and reproduce it.

so if i get this far the protection should be already done or is this a part of the protection ?!


is there a debugger available ? so we can see where it hangs and why


i just made some more tests if i use JP_MegaCD2_22121992_regionfree.bin i can play my jap games and us but for example sensible soccer eu just hangs with a black screen.

 

That's why I recommend using the JPN bios. That happens because the Japanese BIOS has an (albeit undocumented) specific set of library routines and Japanese games may call them. Because all US/PAL (PAL games might "crap out" due to video settings being 60hz so aways try to run them with the machine in 50hz) will work correctly on JPN BIOS it's the most "universal" BIOS you can have.

Heavy Nova in particular seems to crash due to the SEGA LOGO program (the one with SONIC) leaving stuff on the system RAM it does not like. Some BIOS like for example the PAL MEGA-CD2 BIOS might boot it if you patch the instruction that calls the SEGA LOGO routine (since the SEGA LOGO checks on the BIOS are patched out, it will work on the modded BIOS... Such a disc will obviously fail on any non patched JPN BIOS security checks of course. :nod

So yes, it's either the game detecting that non JPN SEGA LOGO has been executed, the game calls routines that only exist on the JPN BIOS or the game goes out of it's way and perform checks on the BIOS itself to test if it's running on a Japanese system.

Games I know you can't play on anything but the JPN BIOS:

3x3 Eyes: glitches badly on FMV
Aisle Lord: freeze on boot
Fhey Area: freeze on boot
Heavy Nova: freeze on boot
Ishii Hisaichi no Daisekai: freeze on boot
Sengoku Densyo: resets the system back to BIOS



These games get either odd FMV or some minor glitches:

Wolfteam games that get red background on FMVs:
Devastator
Tenbu Mega-CD

Game Arts game that has garbled copyright screen on load:
Gambler Jikocyushinha 2


Basically it seems like these problems are intentional. :shrug:

 

but on the jap bios JP_MegaCD2_22121992_regionfree.bin sensible soccer eu just hangs with a black screen... so sadly not all eu games work on the jap bios.

can you make a version that skips the sega logo ? maybe then more games will run.

i also tryed the original regionfree bios ( bios megacd world 1.0 ) but with this version hevy nova crashes earlier eg no music is played, so with the patches you made were are getting a few steps further to play the game.

 

The original region free bios is RAQ's PAL bios for front loader PAL MEGA-CD. Is that one you mean ?


Edit: FYI, I tested Sensible Soccer with the MEGA-CD2 JPN bios on KEGA FUSION and the emulated MD set for 50HZ. The game plays perfectly.

Under NTSC settings I got a nice black screen with a blue window where the following text can be read:

"THIS GAME CD IS ONLY DESIGNED TO RUN ON A EUROPEAN MEGA DRIVE SYSTEM"

I can't patch games detecting the Mega Drive console settings by changing the BIOS so make sure your MD system has language and Hz switches installed. The region free BIOSes have regional settings detection disabled for themselves only.

 

yes thats the one i mean with the bios you patched we have the music played but the game wont start so i think maybe its only a litte thing you have missed to patch.

on RAQs bios the music wont even start.

thats why i was asking for a debugger so we can see why the game hangs but the music is played.

or maybe we can only change the gfx from the us/eu to the jap bios this would be perfect.

 

You're missing the point. The game checks if the actual Mega Drive console is a European unit. If it's not the game shows the region error screen. Still nothing about the BIOS is preventing it from running, which is still true to my statement about the JPN BIOS running all games. :shrug:

Set your MD to PAL/50hz while running the JPN BIOS and the game will work.

 

I'm listening...

Region free bios....how?

 

ok so the jap bios will play all games fine if i have a 50/60 HZ and region switch right ?

but look at the attached image it would be nice to have this in english.
it would be great to replace the japan writing with english.

i dont know if the text on the startup screen ( where it says "NO DISC" on a us/eu mcd) is a picture or a font.

if its only a picture maybe we can replace it with the us/eu one so we would have a perfect jap bios with english text.

habe you ever tried to modify the text ?

thx

 

Take requisite modified BIOS file from this thread and write it out to an appropriately sized EPROM (after byteswapping). Remove maskrom, install socket if desired, insert chip and enjoy.

Supposedly using desoldering braid on a SegaCD 2 is a bad idea but I've removed the EPROM before without any trouble.

I don't have any 256kb EPROMs on hand or else I'd offer to write one out; Bad_Ad84 likely does though.

 

Yes, yes he does.

Not many though, maybe 5 left or so.

 

You can simply put 4 different roms on a 27C4096 (easier to find than 27C1024 I think)... :thumbsup:

 

Finally my programmed EPROM arrived, fitted it and now my european MegaCD speaks japanese!

Thanks everyone for the help

 

All the big text in japanese are compressed tiles, not fonts. Even on the english version they use tiles so you won't find any text inside the BIOS.

Also translating that is a bit beyond my knowledge, sadly ... :shrug: