Cyvern Conversion

djsheep · Jun 7, 2018

Anyone out there know what's involved for a Cyvern conversion / suitable donors.

I'm reading it's just drop in some roms and that's it?

Cheers.

twistedsymphony · Jun 7, 2018

There are 4 different ROM board versions but they're all functionally identical AFAIK.

If you want to keep the same ROM board that Cyvern was meant for you want a ROM-2 Board which is also used by Jan Jan Paradise... the cheapest Super Nova game you can buy: https://auctions.yahoo.co.jp/search...=&sc_i=&exflg=1&p=ジャンジャンパラダイス&x=0&y=0&fixed=0

There are two socketed program ROMs but everything else is SMD. so like the PGM conversions and NAOMI cart conversions it will require desoldering the original SMD ROMs and soldering in new ones along with a 3.3V conversion to power them.

I don't know what needs to be done for protection. I believe these games use a PLD for protection so either that needs to be reproduced and swapped out, or the ROMs need to be patched and I don't believe any of that has been made available publicly.

rewrite · Jun 7, 2018

I've offered before, and I'll offer again. If anyone wants to look into this and is capable of dumping the ROMs and exploring the PLD I have a conversion I'd lend to the cause as long as it returns in the same working condition it leaves in.

edwin128 · Jun 7, 2018

rewrite said:
I've offered before, and I'll offer again. If anyone wants to look into this and is capable of dumping the ROMs and exploring the PLD I have a conversion I'd lend to the cause as long as it returns in the same working condition it leaves in.

Sometimes science needs sacrifies to advance :saint:

yes, we should try to do something similar as it was done for the PGM conversions.

twistedsymphony · Jun 7, 2018

The difficulty of dumping depends on what needs to be dumped. we may only need the program ROMs dumped which would be trivial since they're socketed EPROMs. easy way to check would be to just dump them and see if it works in MAME with the unmodified graphics and sound ROMs.

rewrite · Jun 7, 2018

twistedsymphony said:
The difficulty of dumping depends on what needs to be dumped. we may only need the program ROMs dumped which would be trivial since they're socketed EPROMs. easy way to check would be to just dump them and see if it works in MAME with the unmodified graphics and sound ROMs.

Makes sense.

I can dump them, but I'm not too keen on how to mess about with them in MAME. I'll try to get it done today and have them uploaded somewhere.

twistedsymphony · Jun 7, 2018

rewrite said:
I'm not too keen on how to mess about with them in MAME

I've only started messing with this recently but generally I'd:

1. Find jjparads.zip (Jan Jan Paradise) and unzip it to a folder in the ROM folder with the same name as the zip. (I believe MAME will load files from a folder and ignore the zip if the folder is present, if not you can always just rename the zip to something else.)

2. Find cyvern.zip and unzip it to a folder anywhere. Then rename each file in your cyvern folder to match the files in your jjparads folder. Finally replace all of the files in your jjparads folder with the newly renamed cyvern files.

3. launch MAME from the command line and specify the ROM name (in this case jjparads) you'll also want to add the flags: -window -debug
You'll see some CRC errors but that's normal since the cyvern files wont match the jjparads CRCs. Launching from the menu wont work as it will refuse to load the ROM due to the CRC errors.

^that would be testing a straight unmodified ROM swap since MAME is loading the ROM images from cyvern but emulating the hardware for jjparads.

Chances are that wont work since those are pure unpatched ROMs, so next, you'll want to dump the patched ROMs from your cart and then name them the same as the matching ROMs in the jjparads folder and then replace those files in the jjparads folder. then try running MAME again.

djsheep · Jun 8, 2018

twistedsymphony said:
There are 4 different ROM board versions but they're all functionally identical AFAIK.

If you want to keep the same ROM board that Cyvern was meant for you want a ROM-2 Board which is also used by Jan Jan Paradise... the cheapest Super Nova game you can buy: https://auctions.yahoo.co.jp/search...=&sc_i=&exflg=1&p=ジャンジャンパラダイス&x=0&y=0&fixed=0

There are two socketed program ROMs but everything else is SMD. so like the PGM conversions and NAOMI cart conversions it will require desoldering the original SMD ROMs and soldering in new ones along with a 3.3V conversion to power them.

I don't know what needs to be done for protection. I believe these games use a PLD for protection so either that needs to be reproduced and swapped out, or the ROMs need to be patched and I don't believe any of that has been made available publicly.

Thanks for the in-depth info, and everyone for their efforts in bringing yet another Joerg "special" to the public domain. Really fiending to play Cyvern again -- it really does have a bit of everything in it as far as the genre is concerned.

If anyone makes a conversion on the forums and wants to sell it, I'd buy one anyday over Mr. ModBios' jizz boards.

Apocalypse · Jun 8, 2018

djsheep said:
Thanks for the in-depth info, and everyone for their efforts in bringing yet another Joerg "special" to the public domain. Really fiending to play Cyvern again -- it really does have a bit of everything in it as far as the genre is concerned.
If anyone makes a conversion on the forums and wants to sell it, I'd buy one anyday over Mr. ModBios' jizz boards.

According to MAME the PLD only checks a specific string the BIOS:

MAME said:
WRITE32_MEMBER(skns_state::hit2_w)
{
hit_t &hit = m_hit;
// Decide to unlock on country char of string "FOR xxxxx" in Bios ROM at offset 0x420
// this code simulates behaviour of protection PLD
data>>= 24;
hit.disconnect = 1;
switch (m_region)
{
case 'J':
if (data == 0) hit.disconnect= 0;
break;
case 'U':
if (data == 1) hit.disconnect= 0;
break;
case 'K':
if (data == 2) hit.disconnect= 0;
break;
case 'E':
if (data == 3) hit.disconnect= 0;
break;
case 'A':
if (data < 2) hit.disconnect= 0;
break;
// unknown country id, unlock per default
default:
hit.disconnect= 0;
break;
}
}

I understand it's only used for region protection so if your motherboard is say, Japanese, then you must use the Japanese PLD.

[EDIT]
This or installing a modified BIOS:

http://www.filedropper.com/supernova-modbios

twistedsymphony · Jun 8, 2018

Apocalypse said:
I understand it's only used for region protection so if your motherboard is say, Japanese, then you must use the Japanese PLD.

Is there no protection beyond the region? does that mean any conversion can be done without patching the game ROMs?

Apocalypse · Jun 8, 2018

twistedsymphony said:
Apocalypse said:

I understand it's only used for region protection so if your motherboard is say, Japanese, then you must use the Japanese PLD.

Click to expand...

Is there no protection beyond the region? does that mean any conversion can be done without patching the game ROMs?

I don't know, possibly not after what I read in MAME, maybe someone with the real hardware could have a go an report here.

pacman70 · Jun 9, 2018

I confirm only need supernova-modbios.

I put photos of my conversion could be useful.

pacman70 · Jun 9, 2018

Also the photos for Sengeki Striker.

djsheep · Jun 9, 2018

Thanks @pacman70, hopefully this aids the quest

oneleaf86 · Jul 31, 2018

Hey guys,

I've attempted to convert Jan Jan Paradise to Cyvern but I can't seem to get it to boot properly. My mainboard is Asia region and came stock with Japanese Bios but I've fitted a Japanese Mobios.
If I boot without the Eproms installed the splash screen is in the correct vertical orientation and freezes on the Kaneko Super Nova logo but as soon as I try to boot with the Eproms in, the splash screen displays in horizontal orientation and also freezes on the same logo.

I've tried with and without the decoupling capacitors on each SOP44 chip and that doesn't make a difference.

I'm guessing it has something to do with programming the M27C801 Eproms but I'm very much a noob when it comes to the technical side of things.

If anyone could spread some light on the situation that would be awesome!

oneleaf86 · Aug 2, 2018

Surely someone most have a rough idea this isn't working

twistedsymphony · Aug 2, 2018

oneleaf86 said:
I'm guessing it has something to do with programming the M27C801 Eproms

have you not programmed these?!

oneleaf86 · Aug 2, 2018

twistedsymphony said:
oneleaf86 said:

I'm guessing it has something to do with programming the M27C801 Eproms

Click to expand...

have you not programmed these?!

Of course I programmed them

. Tried various different Eproms and it's always the same outcome. Like I said, I'm very much a noob when it comes to the technical side of things.
It seems like such a straight forward conversion so I'm a bit perplexed as to why I can't get it boot.

twistedsymphony · Aug 2, 2018

oneleaf86 said:
It seems like such a straight forward conversion

I don't know that it is. There was a lot of assumptions that the ROMs AMB was using for the games had been patched. Apocalypse above seemed to imply that might not be the case, but I don't believe we've had a hard confirmation either way.

There are also two PALs on these carts and it's unclear if those need to be changed as well.

oneleaf86 · Aug 2, 2018

twistedsymphony said:
oneleaf86 said:

It seems like such a straight forward conversion

Click to expand...

I don't know that it is. There was a lot of assumptions that the ROMs AMB was using for the games had been patched. Apocalypse above seemed to imply that might not be the case, but I don't believe we've had a hard confirmation either way.
There are also two PALs on these carts and it's unclear if those need to be changed as well.

The roms definitely could have been patched but @pacman70 did state that all he needed was the modbios to make it work.
I attached a picture of a legit Cyvern cart and the Pals are identical to Jan Jan Paradise.

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