Ode to Arcades 2: CBOX MVS and JAMMA Console

This entry is part 2 of 2 in the series Ode to Arcades


Over the past year or so, the CBOX showed up unceremoniously on the various import websites (Alibaba, Aliexpress, TaoBao). It’s gone through a few hardware iterations and is now available locally on eBay and Amazon, though at a higher price. The CBOX is at its core a consolized Neo Geo MV-1C motherboard. This concept is nothing new and intrepid individuals have been consolizing Neo Geo motherboards for many years. The original CBOX came in two flavors, one with Neo Geo controller ports and one with Neo Geo and Saturn ports. It output RCA, S-Video, Component (optional extra), and RGB video and mono sound. It’s biggest hook was the price, you could buy one for under $200, a steal for anyone wanting to play their Neo Geo MVS games on their TV with original hardware! And with the proliferation of the XXX in 1 cartridges, you could get a full setup for around $300.

There were a few drawbacks though like monaural audio. One of the great things about the Neo Geo MVS is its great stereo sound and it was a shame to have to make do with the downmixed mono. Also, when using RGB video, the sync signal output higher than expected voltage, which could (and reportedly did) fry some delicate equipment like the OSSC (Open Source Scan Converter)! In addition, most units had the MVS battery removed so settings and high scores would not be saved after turning the power off. I also read that there were some issues with the Saturn controls but I could not find what those issues were.

Over time, the sellers/manufacturers altered the design, taking feedback from buyers. Units began including the MV-1C stereo mod, pulling audio from a few points on the motherboard instead of the JAMMA connector. For a brief period, sales were halted for while the manufacturer worked out the Saturn control issues. I went back and forth with my seller (Timeharvest Online Store) asking several questions and they informed me that the RGB sync voltage is safely attenuated now. I haven’t confirmed the voltage myself, but I don’t have any reason to believe otherwise. Also, if you want a battery and have a bit of soldering skill, they aren’t too hard to install, or maybe, like I did, you’ll find a surprise in your CBOX (more on that later)!


The version of the CBOX I decided on has all of the consolized Neo Geo MVS features of the previous iterations with one new feature: it can also play JAMMA PCBs. The Aliexpress item has the following, confusing, title …

“New Arrival 2 IN 1 CBOX MVS SNK NEOGEO CMVS + JAMMA CBOX converter with power adapter for 161 in 1 Game Cartridge & Pandora box”

I had been contemplating buying a CBOX before since I own a slew of Neo Geo MVS cartridges, but when I saw this one show up it became a no brainer since I also own several JAMMA PCBs. Do note that this version is considerably more expensive than the Neo Geo MVS only version and it clocks in at $298 + shipping. Luckily I had a birthday coming up which helped make up some of the cost.


The default color for this version is red and I like it quite a bit (I think it’s possible to get this in black or clear as well). The red reminds me of the old big red Neo Geo MVS cabinets that were so prevalent in the USA. The outside casing is acrylic, held together by screws. The silver screws on the bottom are holding the PCB in place and the small black screws are holding the case together. They are actually screwed into the edges of the acrylic, so you should be very careful when taking it apart and screwing it back together. If you look closely, you can see a white coating on all of the acrylic. Normally, when I’ve worked with acrylic, it comes with a protective plastic coating that you peel off before putting it together. I think this may be the same stuff, but I actually think the art is on the opposite side so I’ve left it on. Another plus is that there are no super obvious and embarrassing typos in any of the branding. The only slightly weird thing is they use MVS-1C when it should probably be MV-1C. All of the ports are labeled correctly, which is especially important for the buttons and toggle switches (MVS/JAMMA, Test)

The JAMMA adapter is a basic functional design and bare PCB. As a result, I’d suggest not touching it while the CBOX is plugged in and turned on. The adapter has a red solder mask, which just happens to match the CBOX exterior. The white labeling stands out nicely against the red background and the various switches, toggles, and dials are labeled appropriately. In addition, it has no less than 25 LEDs to indicate various control modes, programming mode, and current inputs. These are super helpful when programming button inputs as the board will light up the current button to assign. The voltage LED display is also a nice addition and pairs well with the +5 volt dial on the CBOX. Some boards draw more power than others and a voltage tweak may be necessary to get them working properly.

Package Contents

  • CBOX
  • DB15 cable to connect JAMMA PCB to CBOX
  • AC adapter AC100-240v to DC12V 8.5A (I got the USA cord)
  • A lot of padding (it was really well packed!)


  • Video:
    • RGB (which cable to get)
    • RCA
    • S-Video
    • Component
  • Audio
    • Stereo RCA
  • Neo Geo MVS
  • JAMMA adapter
  • JAMMA test button
  • +5v potentiometer
  • LED lit power switch
  • 2x Neo Geo controller ports
  • 2x Saturn controller ports


I originally tested Component video on a LCD TV and it looked OK, but not great. I’m guessing something like an OSSC would help a lot in this regard, line doubling or tripling to something modern LCD TVs are more acquainted to dealing with. While waiting for the RGB cable to arrive I used S-Video on my Sony PVM broadcast CRT monitor. S-Video actually looked really great and I was pretty happy with the results. When my RGB SCART cable finally arrived and I switched it over, I was blown away by how great it looked on the PVM. So, while S-Video looked pretty nice, RGB is still much better. I’m guessing Component on a CRT would look pretty fantastic too, but I didn’t try that.

Samurai Shodown 2 “Story”

The RGB cable I went with was the “SNK Neo Geo PACKPUNCH AES / CDZ RGB SCART cable” with the “Stereo CD/CDZ” option from Retro Gaming Cables. The cable pulls RGB from the DIN connector and Stereo Audio from the RCAs and sends them out to a SCART connector. I wasn’t totally sure if this was the right cable when ordering and Retro Gaming Cables was pretty unhelpful when I asked about it. Luckily, I ordered the correct cable and it worked out.


My audio setup consists of a Maker Hart Loop mixer that allows me to take several audio sources and send them to a set of M-Audio AV40 active studio monitors. Neo Geo sounds great with this setup. The mixer also has a headphone connector which I tested as well and I was very surprised at how clean and crisp the audio is when using headphones. I can also say that the system is clearly outputting stereo.

Voltage Potentiometer

The +5V potentiometer works and the label indicates that it can vary the voltage from 5.15V to 5.3V. These voltages may seem high; however, having a game connected will cause a voltage drop, so usually the voltages start around 5.0v, which is more reasonable.

One thing to note, the JAMMA adapter has an integrated voltage indicator that is pretty handy. Unfortunately, you can’t view the voltage when playing MVS games. Even more unfortunate, I believe the voltage pot still functions when in MVS mode, so you may want to turn it down after playing JAMMA games so as not to overvolt the MV-1C motherboard.


Overall, Neo Geo MVS games works very well. I’ve seen no degradation in audio or video. I tested playing original games, bootleg games, and a 138-in-1 cartridge and all worked without issue. Strangely, the 138-in-1 works better in the CBOX than with my MV-1FZ. I get none of the audio issues that plague these cartridges when using it in the CBOX. All I can think of is that this cartridge works better with MV-1C boards than they do on others.


I’m able to use Neo Geo wired arcade sticks and original Sega Saturn pads. Unfortunately, the new officially license Retro-bit Saturn controllers do not work properly in the CBOX. I get duplicate inputs only when using these so I’d stay away from them. In fact, I have an old knockoff Saturn controller with turbo switches that works really well when the Retro-Bits do not.

Knockoff Saturn pad

One perk to using a Saturn pad is the ability to switch between 6 different input modes on the fly at any time. (thanks to pwnmonkey at Reddit for the deciphering the different modes)

L + R + Start + <button in this column>ABCD map to Saturn Buttons
(This mode is great for SHMUPS like Blazing Star)
* ABC_ (manual)
* XYZ_ (turbo)
(Button D is not mapped in this mode)
ZABCX (turbo)

Universe Bios

UniBios Boot Screen

The CBOX comes with UniBios v3.3 installed. Looking at the MV-1C motherboard, it looks like they replaced the original bios chip. They did a good job though and I wouldn’t have been able to tell if I wasn’t looking for it. All of the functionality is there, including in game memory patching, cheats, and soft reset. Reading over the distribution policy at http://unibios.free.fr/, I was pretty sure the inclusion of the UniBios was a breach in license and I doubted the CBOX manufacturers obtained permission from the creator, Razoola. The download page requires that you agree to a list of 7 statements before downloading the UniBios. The sellers seemed to have ignored 4 of the 7:

  1. The UNIVERSE BIOS will be for your sole personal use only
  2. Not to distribute the UNIVERSE BIOS in any way (physical or digital)
  3. Not to included the UNIVERSE BIOS in any product that is sold
  4. Not to alter the UNIVERSE BIOS image file in any way
    1. Notice the TIMEHARVEST CBOX MVS text

So I reached out to Razoola asking about the situation and was surprised to find out that it was all on the up and up.

That is a special UniBios version they can use where permission has been agreed. This UniBios version however is not eligible for free upgrade to newer UniBios versions (like v4.0).


So yeah, my assumptions were unfounded. TIMEHARVEST has, diligently, licensed the UniBios for their CBOXes but, if you want to install a newer version, you’ll have to purchase a new v4.0 ROM from Razoola at http://unibios.free.fr/ as well as a NeoBiosMasta (or NeoBiosMasta VMC) from https://www.neogeofanclub.com/.


After ordering the CBOX, I ordered a CR2032 battery holder thinking I would be doing my own battery mod. To my surprise, when I opened the case, I was greeted with a pre-soldered battery mod.

Battery Holder Close Up

I have to say that I’m not sure if all of these CBOXes come with the battery mod now. Since the manufacturer is using old MV-1C motherboards, it’s entirely possible the board was pre-modded before the CBOX manufacturer even received it. What I’m saying is, don’t make my mistake, wait to get yours before ordering a battery holder.

As for the battery mod itself, it should be visible in the images that D5 has been removed, which I believe should disable the charging circuit. This is necessary because the original battery was rechargeable, but this now takes a CR2032 which is not rechargeable.

Stereo Audio

Images of the stereo mod and connection to custom CBOX board.

It’s pretty great that the stereo mod uses a connector to attach to the custom CBOX motherboard and isn’t directly soldered. It definitely made it easier to disassemble and take photos.

JAMMA Adapter

  • Voltage readout
  • Supports 6 button with kick harness
  • Brightness toggle
  • Stereo toggle
  • Sync toggle
  • Horizontal and vertical offset potentiometers
  • Customizable buttons
  • Auto fire option

JAMMA Controls and Kick Harness

The JAMMA controls function mostly as you would expect. Normally, when booting up a JAMMA game, I’ll go through the input remap (Start + Coin + Up) then be on my way. It’s useful to note that there are 3 JAMMA control modes. Two of these modes seem like they are only useful for playing 6 button games on a 4 button cabinet.

Start + Coin + UpRemap direction and 6 buttons
Start + DownMode 1: Use buttons 1-6 normally
Start + LeftMode 2: Use buttons 1-4 normally
* Button 5 = Buttons 3+4
* Button 6 = Buttons 1+2
Start + RightMode 3: Use buttons 1-4 normally
* Button 5 = Buttons 2+3
* Button 6 = Buttons 1+2+3

The kick harness connectors for player 1 and 2 are a standard 3 pin connector used for PC fans. I purchased some fan extension cables, cut off the male end, and wired them to a DB9 connector since that’s the standard I use for my various JAMMA kick harnesses.

If you want to wire up your own 6 button stick to plug in to the Neo Geo controller ports, the table below has you covered. This follows the normal Neo Geo pinout with the addition of Kick 2/3 on pins that normally have no signal. It’s important to note that this pinout is slightly different than other Neo Geo+ pinouts you can find elsewhere online. Measure twice and solder once.

2Kick 310Kick 2
4Kick 112Punch 3
5Punch 213Punch 1

One caveat, button 4/Kick 1 is sent both to the JAMMA edge connector and to the kick harness. For most cases this is totally fine, unfortunately, I have one of the rare games that handles this incorrectly, Vampire Savior. While Vampire Savior doesn’t use inputs after Button 3 on the JAMMA edge connector, it still detects them as player input which causes problems with certain moves (Morrigan’s Darkness Illusion). You could get around this by creating a special breakout box to extract button 4/Kick 1 from the controller signal and send it straight to the kick harness. Easy but tedious. In a tournament setting you will certainly need to do this.

Saturn controllers in JAMMA mode map to the following:

XButton 1 / Punch 1
YButton 2 / Punch 2
ZButton 3 / Punch 3
AButton 4 / Kick 1
BButton 5 / Kick 2
CButton 6 / Kick 3


I usually leave the brightness toggle off since turning it on gives a pretty bright screen. My guess is that there are situations/games that output a lower than average video signal and toggling this on can help bring video more in line with what is usually expected.


I’m not completely sure what this switch does. I do know that it’s activating some kind of circuit allowing the use of the H/V offset potentiometers. It would be nice if it was a sync separator or something. I’ve contacted the seller to get more information as to its use but haven’t received a response that could help me understand exactly what it does.

Horizontal and Vertical Offset

The horizontal and vertical offset potentiometers seem to do nothing when the sync button is toggled off. Once it’s on, they will move the image as expected, left/right and up/down.


I have not tested the stereo switch on the JAMMA adapter, as the only reason I see for doing so would be to connect it to a multi-slot Neo Geo MVS board and I have no intention of using the CBOX for that purpose. I just leave it on mono mode.

The Guts

CBOX Motherboard

Peeling back the exterior reveals some interesting and unexpected findings. In previous versions there were two small boards, one at the front and one at the back that handled all of the CBOX features. With this updated design, there’s a large, full length adapter board beneath the MV-1C Neo Geo motherboard that handles much of the CBOX features, and a small JAMMA adapter board connected to the MV-1C edge connector.

Miscellaneous Insides

Closing Words

In my opinion, the CBOX is a well thought out piece of kit that does everything I could want it to. It looks good, plays good, and sounds good. It has given me a renewed joy, playing Neo Geo cartridges and JAMMA games, inside the house for once! The only thing I could see them adding in the future is analog to digital video (and audio?) circuitry allowing for HDMI. I think they could easily do this with the open source FPGA project NeoGeoHDMI. Of course, this would mean an increase in price but also allow it to compete with other offerings, like the occasional homemade CMVS’s that show up on eBay or the AES from NeoStore.com. For now, if you absolutely have to play original Neo Geo hardware on your new TV, get an OSSC or, if you like tinkering, roll your own.

Series Navigation<< Ode to Arcades 1: What Made Arcades Special?

28 thoughts on “Ode to Arcades 2: CBOX MVS and JAMMA Console

  1. Is it possible to hook up a Pandora’s box to this MVS Cbox maybe using an adapter? will buttons a,b,c,d be recognized the same? An would I need to change voltage every time I switch from one system to the other?

    • The CBOX should support any arcade board that abides by the JAMMA standard along with the 4th button coming from the JAMMA edge connector (Neo Geo style). It looks like Pandora’s Boxes come in a Home/Family version and Arcade/JAMMA version, you probably want the arcade version. I scanned through the Pandora’s Box 6 manual and the JAMMA pinout looks reasonable (although they seem to map all 6 buttons to JAMMA pins which isn’t quite standard). Having said that, I do not own a Pandora’s Box and I have no experience with them so definitely do your research. As far as voltage goes, I mostly set it and forget it. There may be the odd PCB that hits the power supply harder where I’ll tweak the knob but I haven’t seen much need to touch it for every board.

    • John, the CBOX will let you connect a Pandora’s box as long as it is Jamma. All buttons are recognized as they would on the MVS cart slot. Also, you will not need to change the voltage, once set, it can stay at that desired voltage as Chris mentioned.

      • One thing I forgot to mention is that if you have a Pandora’s box 6 or any PB with multi resolution settings, you will need to set it at the lowest resolution (CRT). This is the only resolution that seems to work on the supergun.

  2. I tried the input remap, and now I can’t use my fight stick! The only commands that work are left, right, coin, and start.

  3. Hi, great info on this unit. Thanks for the write up.
    Can you explain what the Voltage Potentiometer is?
    I just purchased this unit and will be playing this with the 161 in 1 multi game cart. What should I adjust the Voltage to considered that I live in Toronto Canada?



    • I think the main use of the the voltage pot is to adjust the 5v supply when running JAMMA games using the cable and JAMMA dongle. Some JAMMA games will cause a larger voltage drop because they need more power so, on rare occasions you may need to increase or decrease the voltage depending on what you have hooked up. What I’m not sure about is whether the potentiometer affects the Neo Geo PCB inside. So I would say, to be safe, use the voltage display on the JAMMA dongle to get the voltage close to 5v and just leave it alone.

  4. Be very careful when attempting any battery mod on the CBOX v2. I have exactly the same battery holder on mine, (purchased Jan 2021) however the underside components were all still in tact.

    I de-soldered D5 to mimic above said configuration and tried a CR2032 battery. Pretty standard right?….Wrong! Fried the unibios, after contacting Timeharvest been informed that the unit should never be used with a battery else permanent damage will occur. Now I am stuck with a $600 paperweight. not much help at all from seller also, who is very unhelpful at this stage.

  5. Hello again mate, I have the same v2 unit and just released that your one is not wired correctly for the stereo mod with the “red, black and white” connector. As previously mentioned I used your article to change the battery to a cr2032 and ultimately killed my motherboard so I ordered a new MV-1C replacement.
    Fitted the new board and used your picture above to re-solder the audio connector to the bottom of the board. The sound worked but it was mono and not sounding correctly. I noticed the sound not being correct as I actually have a second unit. Please NOTE that the correct soldering of the connector should be RED to LHS R96, BLACK to LHS R103 and Yellow to RHS R103. The 2 sound channels connect to the points on the motherboard to each of the 2 visible tracks going to the resistors which route to the sound IC on the other side of the pcb which is a common stereo mod for this type of board.

    • Hey Konrad,

      I foolishly stuck a battery in there before I read the comments here. I used a rechargeable battery instead (ML2032), so far it seems OK, but I am paranoid. I figured if it’s wired incorrectly, the battery simply won’t charge. How quickly did your board fry? Was it immediately or over a period of time? Should I go take the battery off?

      • @NerdyBros, garbled mess is watchdog error, probably a dead board mate. IF it was working for a few days most likely a cactus board not a fault of the new rechargeable battery.
        The safest option IMO is a supercapacitor as mentioned above. Working very well in my unit with a replacement MV-1C. Don’t expect anything from Timeharvest, I asked him for a replacement board at the beginning and he wanted to charge me 200USD, same board same unibios 3.3, no battery same spill about don’t use a battery and you can’t save story. So i bought a board myself and had a go at a full upgrade and never looked back. Its not that hard.

  6. And… my board died. Not sure if it had anything to do with inserting the ML2032 battery in there or not, but it did go against what the seller suggested. I figured using a rechargeable battery would have been pretty risk free. It worked for a few days, got a crash in the middle of Sengoku, and now it only boots to a garbled screen. @Chris, has yours been OK with the battery? Separately, since my board went bye bye, do you think I could use the CBOX connector to just plug a 1Z board instead? What do you think?

    • just buy a replacement MV-1C board off ebay and carefully upgrade it, but a stock one with the battery intact that has not been tampered with as you just don’t know what was done to it. Make sure its working and tested, ask the seller. Also make sure there is no leak damage and verify with the seller that the bios settings save eg time and date.
      Once purchased its a straight swap out on the CBOX, just wore the sound connector correctly, get a super capacitor and a NeoBiosMasta 2020 Version, the better option is a NeoBiosMasta VMC which gives you added memory card functionality.

    • I have not had any issues with mine. I powered it on just now and everything is still ok. The battery circuit may not be correct as it gobbles my battery very quickly. It seems possible that something else is drawing power from the battery while powered off and there may be more components to desolder than what was done initially, coming from Timeharvest.

  7. Hi All, so if you inserted the new battery which was rechargeable then technically it should not have damaged the board, if you are getting as a RAM error on boot (as in ram mismatch read not matching write). First try to clear you NVRAM from memory. Go into hard dip by pressing BCD or test button on boot. Then in system tests and keep pushing start button until you get a clear memory prompt on screen and clear it. This might resolve your issue IF you are having RAM mismatch error after inserting the rechargeable battery etc. The timeharvest guy is useless, for someone that supposedly invented this CBOX CMVS to tell everyone not to use a battery is plain stupid!. I can’t believe you can supply a unit without a battery to save the unibios settings.
    Anyways, since my last post above I have purchased a new MV-1C board, done a full recap on it, installed a Panasonic 1.5F 5.5V super capacitor instead of a battery (no need to disable charge circuit and leave stock) and a Neo BIOS Masta – 2020 + unibios 4. The system works wonderfully now as it should.
    NeoBiosMasta 2020 Version:
    Panasonic 1.5F Supercapacitor Mfr. Part No. EECS5R5H155
    Please note any 5.5V super capacitor will work, the MVS charge circuit will only charge the cap to a 3V level, the 1.5F cap will hold the settings and charge for about 4 months time without power. The advantage of a supercap over a battery is that the super cap also charges instantly.
    Also again, as per my previous comments check your JST 3 pin audio connector if your sound is not quite right.

    • I am trying to find info regarding supercapacitors use on MVS. But i read about very common supercapacitor failures (leakage) on NAOMI boards. So i wonder if they are really safer than batteries.

  8. @NerdyBros, garbled mess is watchdog error, probably a dead board mate. IF it was working for a few days most likely a cactus board not a fault of the new rechargeable battery.
    The safest option IMO is a supercapacitor as mentioned above. Working very well in my unit with a replacement MV-1C. Don’t expect anything from Timeharvest, I asked him for a replacement board at the beginning and he wanted to charge me 200USD, same board same unibios 3.3, no battery same spill about don’t use a battery and you can’t save story. So i bought a board myself and had a go at a full upgrade and never looked back. Its not that hard.

  9. I’ve got a USB version last year, and something really strange has been going on with my unit.
    Using component video, whenever I plug a USB controller on port 2, a lot of interference starts building up on the screen overtime. It doesn’t matter if another port is being used or not, and it doesn’t happen if I use any of the DB15 ports (eg using USB port 1 and DB15 port 2). I can replicate the same issue using composite video, but it’s way more subtle, and it goes away after some seconds. It happens both in MVS and JAMMA modes. Unfortunately, I don’t have what’s necessary to test it with RGB.
    I had the same issue happening on USB port 1 when I was building an USB arcade stick that had a 5v LED stripe connected to a Brook board. But as soon as I removed the LED stripe, the problem went away. So back then I imagined it was my fault and moved on.
    I’m kinda new in this hobby, and my electronics knowledge is limited. But I would assume something fishy is going on between the USB and the RGB-NTSC decoders? Has anybody else faced this issue? Can someone point me at what direction should I start investigating?

    • Are you plugging component out straight to tv? I ask as you might bust your tv, the component needs to go via scaler such as OSSC or retrotink or rad2x. It’s a raw signal. I am running RGBS out to OSSC.

      • I had no clue that it wasn’t safe to feed the component signal directly to the TV. But now that you mentioned it, I have an older Samsung that handles it fine and a newer LG that doesn’t. This might explain it.
        I have a retrotink, and the issue I described in the previous post happens regardless of it being used or not.
        If component direct to TV is not safe, connecting the CBOX to a PVM through component is a no go?

        • i couldn’t say but i know the component and RGBs signals are non standard and you need a upscaler. I can tell you for a fact that some youtubers use the retrotink scart version with the RGBs out and it looks fantastic, I use OSSC and its great too and looks incredible on my Samsung 4K at 5x scaling with tiny scanlines. An OSSC is really cheap these days from Aliexpress, I use that as I have a fair few scart enabled 240p consoles.

  10. Thank you so much, @Konrad. I had a feeling that maybe it was coincidence, but given that he advised me to not put a battery there, and I did it anyway, I didn’t have much ground to stand. I’m consoling a M1FZ which will make the BIOS swap easier, but I did order a new M1C board for the CBOX, so I’ll check out the super capacitor install. Thank you for the video!!

      • just replace the MV-1C and fix up your CBOX. Buy one stock stock with battery present that way you know you are getting a working unit. Then just buy a supercap and neobiosmata + unibios 4 and your golden, not super expensive.

  11. Thanks for this great detailed review.
    The Jamma connector uses a DB15 cable; how do they “squeeze” all JAMMA (56 pins) signals thru that ? I’m no electronics expert at all. Do you think there is any lag added by this approach vs full JAMMA connector ?

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