What's new
By:

Lei Shen Zhuan / Battle Garegga hack - Help / Advice needed

yosai

yosai

Enthusiast
Joined
Sep 29, 2015
Messages
265
Reaction score
203
Location
London
I picked up a "Lei Shen Zhuan Thunder Deity Biography" PCB a few months back, this exact PCB I believe.


Looking through MAME shows that the game uses the same asset files as Garegga but has modified program file and these additional files.

text.bin is a modified text.81 file containing the Chinese logo and some other shite.
base.bin. Not present in the Garegga set. No idea what this does, the game still works with it missing. :rolleyes:

The main program code is in 27c8100.mon-sys. This looks like the two Garegga program files prg0.bin & prg1.bin have been interleaved and byte flipped. Writing these combined files to a 27C8100 was successful and the game booted but with a slight issue.

Left original Garegga ROM. Right, LSZ ROM using Garegga program file.

BG.png



The entire top layer of graphics are shifted 1/4 way up the screen. This is what it looks like during play, the score and player stock are missing and the bomb stock is way to high. X/

BG2.png



Other than the entire layer being shifted up it looks, sounds and plays fine in both MAME and the PCB.

I couldn't find any info in the MAME driver with regards to differences between the two ROMS.

Any suggestions on how to move the top layer of graphics back to their correct position?

Thanks.
 
base.bin seems to be a kind of table, might be useful after all.

Try with the text.bin file from Lei Shen Zhuan Thunder Deity Biography and report.
 
I have several of these PCBs, and did some poking around a while back.

I have created a hack that mitigates the hardware problems with this PCB, so that the original Battle Garegga game plays on it without issues (misaligned background layers, background updates lagging 1f behind the sprites)

https://github.com/mikejmoffitt/bgaregga-bl-fixes

The bootleg PCB also has no bypass capacitors so I recommend adding them all over the board. There aren't spots for them, so you will need to be creative.

If the text plane is shifted on your bootleg PCB, that's weird - from all the ones I've tested, the text plane doesn't support any kind of positioning, and running stock Garegga on the PCB will actually cause a lot of issues with text layer corruption as a result.

"BASE.BIN" isn't "needed" for the game to run, and MAME makes no use of it. The bootleg PCB, though, absolutely needs it. MAME doesn't run these bootlegs accurately, as the hardware flaws are not represented.

Unzip bgaregga-bl-fixed, burn prg.bin to a 27C800, and text.bin to a 27C256. Have fun desoldering the ROMs from the bootleg PCB, as it's such an utterly garbage quality PCB. Annular rings abandon the attached vias without a lot of force.
 

Attachments

Last edited:
Many thanks for this Mike, excellent write up too. :thumbsup: This is the bgerggabla set from MAME but hopefully it won't be too different.

I'll write them to a couple of EPROms when I get a bit of time and let you know how it goes. Luckily for me the program ROM on my board is socketed, but as you say the build quality on these boards isn't great so swapping 27C256 will be painful.
 
So I burnt the program code to a 27C800 and it worked a treat. :thumbsup: Thanks again for this Mike, I really appreciate it. The board plays surprisingly well, there is a bit of sprite flicker when the screen gets really busy but overall I'm really surprised how well this board performs.

1.jpg


The propeller positions are pretty much bang on.

2.jpg


The only thing left to do is swap the 27C256 but I'll access the condition of the board prior to trying that.

I had to byte flip the program code so I've attached it here, probably not useful for anyone else but you never know. :)

View attachment bgaregga-bla-fixed.zip
 
Oh, interesting - if your title logo is already correct, the you can probably skip the 27C256. On the ones I've had, the TEXT.BIN image was modified to replace the Garegga logo.

I do recommend still adding 0.1uF capacitors all over the board!
 
The title screen logo is correct. The text.bin file contains the attract mode logo which is lightly smaller in resolution.

Hatsune Mike said:
I do recommend still adding 0.1uF capacitors all over the board!
Click to expand...
Thanks, I've already ordered a batch. :thumbup:
 
Right, it's been a while so I forgot. The large logo is on the GP9001's scroll plane.

I have a theory that this PCB's got one frame less lag than the original game after my patch is applied. After I repair a few of these that I still have on the bench, I can finally do some real proper testing to confirm or deny it.
 
In the same boat here and I can confirm.

I had a Battle Garegga bootleg which is the same set as "bgareggabl", the PCB is slightly different than the one linked above.

I was able to flash the program rom with yosai's one linked above. Waiting to flash the text.bin to get a proper attract logo.

Regarding the quality of the pcb and the annular rings, wouldn't it be easier/safer to just cut some legs and install a socket piggyback style on top of the rom ?
 
It depends on the tools you have to remove the EPROM. installing a socket is definitely a good idea.
 
I got a PCB in from someone who wants theirs overhauled so I should probably detail the changes and what it does in a video or something.
 
These boards intrigue the shit out of me.
I kinda want one.
Posting to follow this info in case I run across one.
 
Very tempted to snag one of these and see what it's all about!
 
  • Like
Reactions: RGB
It’s not a copy good enough to warrant doing that. I’m afraid that the mister might be dominated by quickly produced cores that aren’t very accurate, and will be self defeating from the start.
 
Yesterday I bit the bullet and added a socket for text.bin
Everything went ok, no issues with the annular rings. Just cut the original ROM pins with pliers, then remove them one by one, finished with de soldering wick.

It would be perfect, but for one issue...

The "flip screen" option doesn't work properly on bootleg PCB's it seems... (mine was manufactured by a company called RedSun RSE)

On my PCB, it seemed Sw2-dip3 had issues staying ON, it was an issue with bad grounding. Maybe it was never meant to be used. (SW3 is missing one dip as well).
I added a jumper from the pin next to it, it is then able to show as ON when in Test Mode.

However, the screen definitely doens't flip.
Kind of a bummer...

I tried the different bootleg sets in Mame, it seems only some layers flip when others don't...

I will try to reprogram the PCB to its original title (1945二代-bgareggabl) an see if it flips correctly (I doubt it).

I guess another way would be to do flip on the monitor chassis, but...

Could the flip be linked to base.bin ?
 
I replaced the text.bin on my PCB and did not have any issues. base.bin was left as the default.

I can also confirm that screen flip does not work on my board (DIP02 SW03) but the screen is the correct orientation already.
 
You must log in or register to reply here.
Back
Top