Purpose

In 2023, a clever developer that goes by the alias Vortex, figured out how to dump and reprogram the Neo Geo 161-in-1 cart that is readily available for sale online. Over time, other members of the community expanded on this work to make this cart even better.

The purpose of this page is to explain what this cart is (and isn't) and help existing owners with issues that they might run into while using it.

What's wrong with the 161-in-1 cart?

While the existing 161-in-1 cart, through its many iterations in the past 15 years, serves a purpose, it is not without its flaws. Some of these include:

• The cart doesn't really have 161-in-1 games. Many are clones/duplicates because the cart doesn't have enough memory to hold the entire Neo Geo library
• Hardware compatibility issues. Cheap or missing components (regulators, capacitors)
• Outdated interface
• Goal of the cart is price over quality

The goal of this project is to fix many of these flaws while working in the constraints imposed by the underlying design of the cart.

What do I do to a typical 161-in-1 cart to convert it to an All-in-1 cart?

Making these carts is a time consuming effort that requires purchasing donor carts, fabricating custom PCBs, purchasing of extra flash memory, components, etc. There's a lot of work and many hours that go into making a single cart.

Specifically, What I do:

• All flash chips are desoldered, reprogrammed with a full set of all clean Neo Geo ROMs (all MVS, AES, some Neo Geo CD ports, some homebrew games), and soldered back to the cart
• The 3 FPGAs are reprogrammed with new code
• A new, modern, game select menu is added
• Extra flash memory is added to make all the games fit using new PCBs
• The power circuits are modified to support the extra memory and fix the bad audio output of the original design
• All the capacitors are replaced with new Japanese Nichicon caps sourced from Digikey
• Other corrections are applied to the cart to improve compatibility and stability
• On average, it takes about 6-8 hours to make 1 cart

You can learn more about the original project here

How does this compare to other SD based carts? (NeoSD, Darksoft)

Every multicart has its pro's and con's. It's up to you to decide what works best for you and what you want from the Neo Geo. Here's my take on the major differences:

Pro's:

• All games instantly start, no waiting a few minutes for games to copy from a micro SD card
• Cost - it is by far the cheapest multicart solution for the Neo Geo

Con's:

• Unable to add / remove games. What makes this cart fast also prevents you from modifying it. All the games are burned to memory instead of waiting for them to copy from a microSD
• Game compatibility - there's a select few games (see below) that don't use the original ROM images
• Hardware compatibility - if an unmodified 161-in-1 cart doesn't work on your Neo Geo system today, chances are this won't either (see common hardware issues below)
• Other limitations - we are working within the limits of the 161-in-1 design. Things like saving dip switches, game states, high score, etc. doesn't work

Tell me more about the game compatibility issues

These are the current known game limitations:

• KOF 2000 has graphical glitches in the menu text but the game is fully playable
• GAROU:Mark of the Wolf is the beta ROM version
• SVC is the "Remix Ultra" version

These game limitations exist because the original games don't use standard Neo Geo carts. They have extra chips to add encryption/memory bank switching added to them. These chips are not reproduced in the FPGA code due to space limitation and as a result compromises had to be made to make the games work.

All the other games use original Neo Geo clean ROM dumps.

Tell me more about hardware compatibility issues

If you have issues running the cart, one or more things can be working against you. The cart itself has been fully tested in my 1 slot MVS-1FZ PCB running in a Sega New Astro City cab. It was also tested using a Furrtek Fusion Converter in my Neo Geo AES. Given the extensive testing the cart has gone through before shipping to you, when issues come up with a malfunctioning cart, we need to figure out what’s different between my setup and yours to solve the issue.

These are some of the issues past customers had and how they solved it:

• Dirty contacts
  • Most common problem that effects graphics or audio
  • Effects the Neo Geo cart and PCB (cart could have gotten dirty by going into a dirty arcade PCB)
  • Using 99% IPA and Q-Tips, get the Q-Tip wet and rub hard and fast against all 4 edges of the cart connector. I normally go through 8-10 Q-Tips doing this. Continue cleaning until the Q-Tip is no longer black
  • Use an electronics rated contact cleaner (I use Deoxite D5) to spray into both edge connectors of the MVS arcade PCB
  • Insert the cart a few times quickly in and out

• Bad power supply
  • Regular MVS carts use on average 700mA
  • This multicart has extra flash memory, and 3 FPGAs. On average it uses >2000mA
  • Use a multimeter to check the 5VDC line and make sure it’s not failing (less than 4.9VDC or >5.1VDC)
  • Try swapping the power supply or test in another arcade machine

• Bad Neo Geo arcade PCB
  • Some Neo Geo PCBs (especially ones purchased from places like eBay or AliExpress) were broken and not fixed correctly
    • For example, the NEO BUF chip was replaced with simple wires. This will work for some carts but not most
  • Try to get a copy of DIAG ROM and test it on your board to make sure you don't have failing RAM or other chips

• UNIBIOS compatibility issues with some PCBs
  
  • We've had some customers get an "Illegal Instruction" screen. Pressing C causes the error to go away the the game plays fine. This is especially true with MV1F and some 2 slot PCBs.
  • This is a known compatibility issue between UNIBIOS, multi-game carts and this Neo Geo PCB revision
  • The only known fix is to remove the UNIBIOS, put the original BIOS back and power cycle the arcade machine to select a different game
  • You can also replace the Neo Geo PCB with a newer revision where SNK fixes the problem in their PCB design

Why don't you make an AES version of the All-in-1 cart?

I used to. But around June 2024, the Chinese factories that make the AES 161-in-1 cart changed the design to one that can't be converted.

Will the MVS cart work on an AES system using a converter like the Furrtek Fusion converter?

It depends on your AES system revision. It's been my experience that for many, it will. But there are some systems that have issues that can not be resolved and are inherit to the AES system used. The failure falls into 3 categories:

• Power related
  • The converter adds another FPGA to the stack, increasing the power requirements
  • 5V systems suffer the most from this. The factory AC adapters don't have the 2-3A required to power everything

• Processor related
  • SNK used Hitachi and Toshiba as its 68000 CPU second source provider
  • The Hitachi CPU seems to handle timing different from Toshiba/Motorola  CPUs resulting in graphical corruption
  • Some customers replaced the Hitachi CPU with a Toshiba one and all their problems went away
• Defective Fusion converter
  • Some Fusion converters might have shipped with defective bus transceivers. Some games work, other give you an "illegal instruction" error.
  • Swapping the 2 no-name Chinese made 74HC245 chips with brand name part (Texas Instruments, onsemi) fixes the problem
  • I documented this failure here 

Keep in mind that Furrtek does not support using his converter with any multicart.

How do I get back to the main menu to select a different game?

It depends on what Neo Geo system you are using. If you're on a CMVS (Consolized MVS) or AES, power cycling / resetting the system is all you need to do.

For MVS (real arcade machines), a custom UNIBIOS V4 has been provided to you with the cart. After you install the BIOS into your arcade PCB, to get back to the main menu you:

• Bring up the in-game menu (http://unibios.free.fr/howitworks.html)
• scroll down to RESET
• While holding the B button, press A to accept to reset the game and the main menu will come up to let you choose a different game.

By default, UNIBIOS only resets the current game; it doesn't kick you out to the main menu. Holding B kicks you back but only on the UNIBIOS I provide with the cart. This feature is important for arcade machines with CRTs since you don't want to power cycle them all the time.