What's new

SwaggaJackin'

Beginner
Joined
Jan 14, 2019
Messages
13
Reaction score
1
Location
USA
Recently picked up raiden fighters jet, curious how hard it would be to be able to play 2 and the 1st one as well using the same cart. Are they completely different hardware or is it something like a PAL/GAL preventing conversions or more complicated? Thanks.
 
I don't think so. There are a few different ROM board variants, and Raiden Fighters, Raiden Fighters 2 and Raiden Fighters Jet are all on different ROM boards.

I believe there are some protection mechanisms that would need to be bypassed too.
 
Last edited:
Necro thread bump!

Is it possible to convert Senkyu or E-Jan High School to Viper Phase 1 New Version? According to MAME, they all use the same ROM board.

I know it would take some surface-mount soldering on the SOP package ROMs, but I'm willing to do that...
 
viperphase can be updated to the new version, but i though conversions were not possible because the protection/encryption stuff in there, maybe things have changed??
 
Last edited:
viperphase can be updated to the the new version, but i though conversions were not possible because the protection/encryption stuff in there, maybe things have changed??
that's my belief... though I've never actually tested in MAME so...
 
viperphase can be updated to the the new version, but i though conversions were not possible because the protection/encryption stuff in there, maybe things have changed??
that's my belief... though I've never actually tested in MAME so...
Ive done it, so that works in real hardware. Problem is you almost never see the old version for sale anymore, from time to time you might see the new version, but thats about it. I think RTW spoke about why conversions were not possible in a thread somewhere.
 
Necro thread bump!

Is it possible to convert Senkyu or E-Jan High School to Viper Phase 1 New Version? According to MAME, they all use the same ROM board.

I know it would take some surface-mount soldering on the SOP package ROMs, but I'm willing to do that...
Oh please yes!
 
as far as I knew Battle ballz and Viper Phase are on the same pcbtype.. would there be a different custom on the pcb of some sort? I need to find a closeup of a VP pcb to compare to my BB.. the plan was to convert it :S
 
Honestly, just because the same PCB is used between games DOES NOT mean conversions are possible. Similarly, just because different PCBs are used between games DOES NOT mean conversion's aren't possible.

so lets take a serious look at this...

Here are the PCBs used and the custom chips on each one.

SXX2C ROM SUB w/ SEIBU custom stamped 'SEI252 SB05-106
-Senkyu / Battle Balls
-E-Jan High School
-Viper Phase 1

SXX2C ROM SUB2 w/SEIBU custom stamped 'SEI252 SB05-106'
-Raiden Fighters

SXX2C ROM SUB4 w/SEIBU custom stamped 'SEI252 SB05-106'
-Raiden Fighters (Asia)

SXX2C ROM SUB8 w/SEIBU custom stamped 'RISE10'
-Raiden Fighters 2

SXX2C ROM SUB10 w/SEIBU custom stamped 'RISE11'
-Raiden Fighters Jet


So these ROM boards have some ROMs and some RAM and sometimes PALs but the only real thing on here that could be providing protection is the custom chip... there seems to only be 3 different custom chips:
RISE10 used on RF2
RISE11 used on RFJ
and
SEI252 SB05-106 used on everything else

looking at MAME source it appears that these customs are used for Sprite Encryption... It's possible that the encryption scheme is the same based on the chip model, or it's also possible that the encryption scheme is unique per game even if the same chip is used.

Assuming there is no additional layer of protection that I'm missing the next step would be testing a virtual conversion in MAME Assuming that the sprite encryption is the only protection the game should boot and play but with corrupted graphics.

if that's the case it might be viable to decrypt and then re-encrypt the graphics for a different encryption scheme.

alternatively it might just work, or it might not even boot. But a MAME test is the next step.
 
I tried a virtual conversion of E-Jan High School to Viper Phase 1 last night. It wouldn’t boot to the board-flashing step-MAME would crash out with an illegal CPU instruction. I’ll try again with Battle Balls tonight.
 
Virtual conversion of E-Jong might not work so well because of the extra IO hardware being emulated.
 
I tried a virtual conversion of E-Jan High School to Viper Phase 1 last night. It wouldn’t boot to the board-flashing step-MAME would crash out with an illegal CPU instruction. I’ll try again with Battle Balls tonight.
How did the battle ballz experiment go? :)
 
I got distracted and didn’t try it yet. I’ll try it tonight. :thumbsup:
:whistling: :saint: Both games share the "same" pcb, and the Custom at least has the same markings... althou theoretically it could of course be programmable with some tricks inside, but I still hope :D

But get suitable replacements for the SMD roms aint going to be fun.. might need to craft small adapterpcbs for other memory types or whatnot with buffers/leveltranslators etc..
Buuuut I would love to get som viper phaze action going!

Battle Ballz PCB
BBIMG_0405.jpg


Viper Phaze PCB
VP1IMG_0405.jpg
 
So I was going through my PCBs earlier and had an idea...

Here's Viper Phase 1 running on an E-JAN PCB:

Also tested on Battle Balls for same effect, will likely work on Raiden Fighters 1 PCB also.

this is with ROMs 1-6 (all the socketed ROMs) swapped and all of the SMD ROMs remaining in place, no other trickery involved... it literally "just works".

The E-JAN graphics ROMs are still in place here which is why you see "flying blocks of crap", but the game seems to boot/play fine.

To complete the conversion:
There are 8 SMD ROMs that need to be replaced for the graphics to work, unfortunately 3 of them are a weird SOP32 form factor.

U215 is the PCM ROM, and luckily it shares all of the address and data lines with U216 which is socketed and unused by Viper Phase 1, so if we remove U215 and jump the CE pins between the two (this works out to 2 adjacent pins on the main board connector so a simple solder blob would do it) it should theoretically allow you use that socket instead of sourcing a SOP32 ROM for that location. That would fix the Audio

U322, U323, and U324 are all 32Mbit SOP44 ROMs (8-bit I think). So they could be replaced with MX29L3211 but would require a voltage regulator to supply 3.3V power. That would fix the object roms.

Finally there is the Background Tile ROMs. U415 is a 16Mbit SOP44 and U410 is an 8Mbit SOP44. I believe you can find 5V SOP44 EPROMs in these sizes, worse case you can use more of the MX29L3211s. I believe these are setup in 16-bit configuration.
The tricky part here is U416 and U49, these are again SOP32 EPROMs, U416 is 8Mbit and U49 is 4Mbit. These are pretty uncommon and I don't know of any suitable models that will work here off the top of my head. Worst case you could dead bug wire up a 27c080 and a 27c040 but that'd be super ugly, there's enough room here you could also build a small adapter PCB to run some SOP44 equivalents or something else

I already have a Viper Phase 1 cart so I don't really have much ambition to take this further but based on my test I'm pretty confident that if you can complete the conversion of Battle Bals/E-JAN or RF1 to VP1 using the above described method.
 
Cool! Did it re-initialize the game?
 
So I was going through my PCBs earlier and had an idea...

Here's Viper Phase 1 running on an E-JAN PCB:

Also tested on Battle Balls for same effect, will likely work on Raiden Fighters 1 PCB also.

this is with ROMs 1-6 (all the socketed ROMs) swapped and all of the SMD ROMs remaining in place, no other trickery involved... it literally "just works".

The E-JAN graphics ROMs are still in place here which is why you see "flying blocks of crap", but the game seems to boot/play fine.

To complete the conversion:
There are 8 SMD ROMs that need to be replaced for the graphics to work, unfortunately 3 of them are a weird SOP32 form factor.

U215 is the PCM ROM, and luckily it shares all of the address and data lines with U216 which is socketed and unused by Viper Phase 1, so if we remove U215 and jump the CE pins between the two (this works out to 2 adjacent pins on the main board connector so a simple solder blob would do it) it should theoretically allow you use that socket instead of sourcing a SOP32 ROM for that location. That would fix the Audio

U322, U323, and U324 are all 32Mbit SOP44 ROMs (8-bit I think). So they could be replaced with MX29L3211 but would require a voltage regulator to supply 3.3V power. That would fix the object roms.

Finally there is the Background Tile ROMs. U415 is a 16Mbit SOP44 and U410 is an 8Mbit SOP44. I believe you can find 5V SOP44 EPROMs in these sizes, worse case you can use more of the MX29L3211s. I believe these are setup in 16-bit configuration.
The tricky part here is U416 and U49, these are again SOP32 EPROMs, U416 is 8Mbit and U49 is 4Mbit. These are pretty uncommon and I don't know of any suitable models that will work here off the top of my head. Worst case you could dead bug wire up a 27c080 and a 27c040 but that'd be super ugly, there's enough room here you could also build a small adapter PCB to run some SOP44 equivalents or something else

I already have a Viper Phase 1 cart so I don't really have much ambition to take this further but based on my test I'm pretty confident that if you can complete the conversion of Battle Bals/E-JAN or RF1 to VP1 using the above described method.
Awesome :). I have been thinking about making som kind of SMD adapter but with active components and leveltranslators for all the IO and small 3.3v regulator for the supply.. but thats alot of work for one game :S
Not made up my mind yet if I should do it or not :). Really want VP1 thou
 
Back
Top