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Reverse engineering 161 in 1 cartridge to change Rom games

Nice ArcadeTV, good job again. That's about all we need at this point.

Has anyone thought about what it would take to get the non proto version of GMOTW running on this cart? I know the rom version from NeoRAGEx 5.2a is fully decrypted non proto. Assume it's still using that custom mapper though. Tried to use the proto Prom but it's addressing data from a different layout. I'm not 100% sure it's using that the custom mapper, but it looks like it is.
 
Next question, what’s involved with taking the C/V ROM chip itself from the stilt (v2) cart and using it as donor for the dual chip on dip v3 daughter board?

Do I need a separate programming board? I have a dead older cart and want to verify at least one of these chips is good for use on a V3. Is it better to keep it on the stilt board or try to remove the IC?
 
kuze said:
Next question, what’s involved with taking the C/V ROM chip itself from the stilt (v2) cart and using it as donor for the dual chip on dip v3 daughter board?

Do I need a separate programming board? I have a dead older cart and want to verify at least one of these chips is good for use on a V3. Is it better to keep it on the stilt board or try to remove the IC?
Click to expand...
It's been my experience that it's best to not only get the dual stilt made (for 3Gb/all games) but also get the replacement stilts made (in another repo by same report owner - @ack). The reason is the original stilts use surface mount headers that are very weak. It doesn't take much to have them rip off the board (many times taking the pads and wires with them). No matter how cleanly you remove the stilts from the main board, a tiny amount of solder stays on the pins. These snag in the programmer.

It's been my experience that I can cleanly remove the stilts in less than a minute. Then run a desoldering station (even with bigger nozzle) over the pins to remove any solder crud left behind. I then remove the Flash from the old stilts, test, program, verify. And you're done. It's very important that you verify. This confirms that all the pins are properly connected and the data is good.
 
I know someone had mentioned how easy it is to make the pins go cock-eyed when soldering them on the new daughterboards and I wanted to offer my advice after having done 6 of them tonight.

Either set your temps /really/ low and do each pin by hand, OR just use solder paste. I've had way better luck and spent half as long on the last 3 as I did doing the first 3 by hand. Paste a bit down each side of the dual pin rows, hot air the paste, quick cleanup with solder wick and off you go inside 3-4 minutes. The paste and hot air means you're not tapping the pins with the iron and they don't get nudged around.
 
@ArcadeTV summerized little bit the process and looks very nice !
Is still WIP and changes are happen very often (will be published on github every changes)


15833761-7EF4-4BF4-AB8F-2F8A00307AD7.png


Me , as a noob who wants to make a cart for himself is looking amazing 🙈

https://github.com/ArcadeTV/neogeo-menu/blob/main/161in1v3_mod_flowchart.pdf
 
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AlxUnderBase said:
Thanks to @Niko for audio fixing of Nightmare in the Dark (sound glitch that causes a scratch noise whenever you jump)

Code:
260-v1.v1:
0x50820: 6E -> 08

In V ROM must be changed a single byte for this purpose !

Thanks @Neo-Alec for your notes ✌🏻
Click to expand...

There's also the Samurai Shodown 5 Special patch:

https://www.arcade-projects.com/thr...al-perfect-improperly-decrypted-v-roms.18187/

No idea how widely circulated the fix is.

And on another MVS related note, a back port of Rally Chase which may or may not be worth adding:

https://www.arcade-projects.com/threads/rally-chase-cartridge-version.24943/
 
AlxUnderBase said:
@ArcadeTV summerized little bit the process and looks very nice !
Is still WIP and changes are happen very often (will be published on github every changes)
Click to expand...

There's a few things that need to be done before the new menu system can be used by everyone:

- a new version of VTXcart.exe is needed that knows how to add the new menu data to CROM and other ICs that the original menu doesn't touch
- the files in the vortex directory are named wrong. They need to be renamed into their MAME names because that's what Vortex called them in his menu\[mvs|aes] directory

So there's still a little bit of work left, but the menu system has been fully tested on real hardware and it works great.
 
Ugh, hit the wrong button...

Anyone have a domestic source for the female 1.27mm connectors? Luckily had a few in a drawer, but not enough. I'd like to snag a handful more while waiting on a bulk order from China.
 
Vortex said:
As for my custom cart - I've made several menu edits relative to the original dump
Click to expand...

@Vortex
May I ask if or what was edited in the AES menu?
Since there is no BackupRAM in the machine I guess it's just the replacement of the MCU routines, right?

Thank You very much!
 
Vortex said:
Forgot to mention.
I also significantly improved the quality of the PCM sound of the cartridge by throwing out the stock 3.3v (actually 3.2 volts stabilizers and installing my own in its place, adjusted to exactly 3.58 volts (the CPLDs are 5 volts tolerant while the maximum voltage on flash memory is 3.6 volts). The logic "1" level rise-up of 0.3 volts (10%), coupled with the correct (improved) timings in the CPLD, gave rock-solid stability. No more distorted or absent sounds in ANY game.

I do not intend to make any profit from my research. If the Chinese copy my work, I think we will all be happy.

Perhaps later I will compile and release a new (third) set of cartridge entirely consisting of homebrew games and other useful utilities. If you have something to share, you are welcome.
Click to expand...

Vortex, can you comment on what you were trying to solve? I noticed some carts I made had really noisy background noise (hiss, like in the menu) and visible noise in solid colors (like neo geo while background had some waves in it) while other carts are as clean as the original carts.

Is this due to voltage regulator? CPLD on CHA PCB that's more tolerant than another? I know the MAX 3000A is more than capable of working with 3.3V and 5V output devices, but is the issue the input voltage?
 
ack said:
The pinout of the jtag connector on the 161in1 boards is

pin 1 = VCC (3.3V)
pin 2 = GND
pin 3 = TCK
pin 4 = TDO
pin 5 = TDI
pin 6 = TMS
Click to expand...

Thanks for the pinout. Which headers are for programming which CPLD?
 
Yami said:
IMHO it would be great if all these resources were collected, cited or linked on a GitHub page, i.e. the one by @ArcadeTV, to get a complete "summary" of the entire conversion project.
Click to expand...

The process itself is sprinkled here and there, but there are some things that I don't think we should bother to document.; common sense stuff that anyone attempting this must first master. Like,

- how do you remove the chips or solder them back?
- what is the correct orientation for the chips?
- where are the programming pins for the CPLD?

Anyone who's soldered, programmed, assembled any PCB before will know the answer to this. Making this cart is really next level and should only be attempted by those who have done this before.

[getting off his soap box and running back down to the basement]
 
leonk said:
Making this cart is really next level and should only be attempted by those who have done this before.
Click to expand...

Why? it's a Chinese multi cart, not some rare, one-of-a-kind thing. If people end up breaking them, who cares.
 
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nem said:
Why? it's a Chinese multi cart, not some rare, one-of-a-kind thing. If people end up breaking them, who cares.
Click to expand...

for this exact reason. All the components on this cart (outside the shell and PCB) are recycled. I've had a flash chip get its legs fall off, another tester had one of the flash chips crack in 1/2 during the removal process; recycled chips aren't as resilient as new chips.

I'm all for people making their own carts; this is an awesome hobby project. I anyone has a technical question about the process, I'll be more than happy to help here. But I want to make sure people are realistic in their skill set; I can't guide a person on how to cleanly remove flash chips from the PCB.

Let me use another analogy.. I'm good with changing oil and tires on my car, but I wouldn't even think of rebuilding the engine and transmission. What we have here is at the "rebuilding engine" skill level when it comes to PCB work.
 
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