It is the early 2000s. Titans are falling: the arcade business sinks to new lows every week, Sega has left the console business, and SNK/Playmore has finally ended the reign of the Neo Geo. And then a pachinko manufacturer decided to take all of those trends, wrap them in a red plastic box, and name it after their founder. Behold, the arcade series continues!

Who is this Sammy guy

To note; the “named after their founder” thing is not confirmed. Specifically, the founder of Sammy Corporation’s name is Hajime Satomi. Take “Satomi”, his family name, move the “s” to the end, and you have Atomis. It could just be a coincidence; maybe they just thought it sounded cool.

Sammy Logo

Sammy Corporation was founded as Sammy Industry Co. Ltd. in 1975 and were an early mainstay of the Japanese arcade game industry. In 1982, they entered the pachinko and “pachislot” business. (Pachislot being a Japanese variant of slot machines where each reel has its own button, thus making it a skill game, maybe) They were also a fairly major publisher. Despite having many arcade platforms, they never released any consoles of their own. You might know them best for publishing the Guilty Gear series.

Guilty Gear X for Dreamcast, published by Sammy

Sega broadcasted its dreams, and no one listened

Sega Logo

The story of the Atomiswave arguably starts at another company, though– Sega Enterprises. In 1998, they released the powerful Dreamcast console, which was marketed as “128-bit” in the last gasp of the bit wars. But Sega also released the NAOMI, a high-end upgraded version of the Dreamcast for arcade usage which, like the Neo Geo and unlike past Sega arcade boards, used interchangeable cartridges. (and later, GD-ROMs) The NAOMI outlived the Dreamcast, continuing to get new games until 2006. I don’t have one of those, so here’s a picture of my Dreamcast instead.

Sega Dreamcast

With the discontinuation of the Dreamcast in 2001, Sammy saw an opportunity in the lower-end arcade machine space; especially outside of traditional arcades, like bars, shopping malls, and other places, which may have had one or two machines. Unlike the Sega NAOMI, the Atomiswave would use the older JAMMA edge connector standard, making it easy to convert, say, an old Street Fighter 2 machine that wasn’t getting much play anymore.

Behold! Atomiswave

Atomiswave logo

The Atomiswave is often described as a cost-reduced Sega NAOMI, and that I guess is accurate; but its specs really are identical to the Sega Dreamcast.

  • 200 MHz Hitachi SH-4 CPU
  • 100 MHz PowerVR 2 GPU
  • 16 MB system RAM
  • 16 MB graphics RAM
  • 8 MB sound RAM

The main difference between the Atomiswave and the Dreamcast, other than using a JAMMA edge connector, is that games for the former are on ROM cartridges. Unlike the Neo Geo cartridges, though, these aren’t exposed to the system’s buses directly, and data must be copied into RAM. This is typical; at frequencies like 200 MHz, you can’t exactly just expose an edge connector and expect to not get wiped out by interference. Therefore, the cartridges are quite a bit smaller.

An Atomiswave cart (King of Fighters Neowave) on top of a Neo Geo cart (King of Fighters 2001), showing that one is much larger than the other

The Atomiswave has multiple removable plastic bays on it; these allowed for connecting different modules, like an internet connection, or lightguns. Lightgun games seem to be a major part of the library; unfortunately, my arcade-at-home setup doesn’t use a CRT, so I haven’t gotten any of those. These were quite popular with the outside-of-arcade arcade market in the US at the time, though in my experience Big Buck Hunter was more common.

An Atomiswave without a game cart

Underneath that plastic shell is an RF shield; interference really starts to become a major issue when your processors are running fast, so I suppose the bare circuitboards of JAMMA machines past had to go. I wanted to get a look at the circuitboard because of that corrosion in the corner near where the battery is; thankfully, the board is fine. I wonder if my particular Atomiswave was assembled from spare parts.

An Atomiswave circuitboard

Getting video from the Atomiswave

So when I saw the Atomiswave’s ports, I was impressed. VGA! This means that you can just plug in one of many VGA monitors, right? After all, the Dreamcast can do 480p VGA video pretty easily. (You might hear this described as “31kHz”, vs. the “15kHz” 240p/480i. That speed is the speed at which horizontal lines are drawn; of course, twice as fast means twice as many lines in a single field or frame)

Atomiswave ports adjacent to the JAMMA connector: Serial, 15-pin VGA, a few dip switches, a volume wheel, and a 'CN3' port

But not so fast. Even though they decided to use the familiar 15-pin connector, and it can indeed output 480p video, this isn’t stock VGA, as it’s designed for an arcade monitor. The difference lies in the “sync”. I’ll do a quick overview, but for more detail I recomment RetroRGB’s take.

Aside: Everything but the kitchen sync

So, any analog video signal is just a continuous stream of voltages. The screen, whether it be a CRT or the decoding hardware of a flatscreen, draws in horizontal lines from top to bottom, and then starts over. This is called a “raster”. (Vector signals work differently, but we’re not talking about those even though they’re cool)

But there is a clear problem: if I plug in a cable, how does the screen know where to start drawing? Additionally, all electronics have tolerances and all timing can be slightly off. If the raster on the screen is at all off from the raster on your game console, the picture will get out of sync very fast. That’s what happened to my poor Apple Monitor /// back in the post on PAL video.

The Monitor III with an NTSC raster failing miserably to display PAL video

Thus, you need a “sync” signal. These are horizontal and vertical pulses; when the horizontal signal pulses, a line is over, and the beam can return to the starting x position. When the vertical signal pulses, the whole field is over, and the beam can return to start. There are a lot of ways to get this signal; see the RetroRGB article I linked for details.

The short bit here: VGA provides two pins for this; horizontal and vertical as separate electric signals (“HSYNC” and “VSYNC”). JAMMA provides one sync pin that provides both pulses; they’re very different lengths, so distinguishing them is easy. This is called “composite sync” (CSYNC), and is annoyingly not the same thing as “Sync on Composite”. But this is an arcade machine so there’s no composite video. Most arcade monitors of the time were built to JAMMA standards, and expect CSYNC.

And that’s the problem with the Atomiswave’s VGA port. Rather than provide separate VSYNC and HSYNC, it provides CSYNC. Great for an early 2000’s arcade operator, but if you try to plug it directly into a TV or computer monitor, you’ll have to be very lucky to get a signal.

For me, I found it easier to configure the DIP switches and get 480p video over the SCART connector on my supergun; but make sure your supergun’s hardware supports this. Both the OSSC and the Framemeister can get 480p over their RGB connectors, but it’s technically not part of the SCART standard. Thankfully, the Atomiswave can also output standard 15kHz video. We’ll talk about comparing those when we get to the games. If I don’t mention, you can assume any Atomiswave capture is 480p.

When we get to the games

Damn, that was a lot of text. Let’s talk about some games and see what this hardware can really do!

KOF XI showing the final boss, Magaki, making a win statement

Well, the games I have aren’t great examples of what the hardware can really do; they’re both 2D fighters from SNK. I’d like to get more games, but this is what I have now. If I get more, maybe I’ll do a livestream or something.

The King of Fighters Neowave

KOF Neowave title screen

This is it: King of Fighters 2004. Well, no, actually. It’s King of Fighters Neowave, it says on the title screen. This game isn’t considered part of the main yearly/numbered King of Fighters series; it seems to have been almost a tech demo, something SNK made to get more familiar with the hardware. It’s sort of a port of King of Fighters 2002, which unfortunately, I don’t have on AES. I do have a copy of the PC port, though.

KOF 2001 PC port title screen

Both King of Fighters 2002 and King of Fighters Neowave are what SNK calls “Dream Match” games; they don’t have a storyline, so characters who are dead like the KOF ‘97 “New Faces Team” or characters who are chronologically wrong like young Geese Howard can still show up. They also have the typical “classic KOF” 3-on-3 match style; these entries tend to be more popular among serious fighting game players; dilettantes who play on “Very Easy” mode like me will just be disappointed by the lack of a story or fun post-match taunts.

KOF Neowave victory screen; the characters are there and so is the text 'WINNER', but no post-match taunt

King of Fighters Neowave also seems to be one of the most widely available Atomiswave games. Of course, there are a lot of bootlegs afoot. We’ll talk about that later.


Atomiswave menu

As an arcade game, the Atomiswave features a service menu, which is controlled using the “Service” and “Test” buttons. There is limited ability to use controllers as well, but only to replicate the function of the two test buttons (you can press down, but not up, for example). This makes sense, since many Atomiswave games were lightgun games that wouldn’t use buttons, but is a bit of a pain.

Another thing that is a pain for a Supergun user is that for the King of Fighters game, the buttons have been rearranged from the Neo Geo arrangement, which for cabinets was usually four buttons in a row. But if you take a look at the Neowave manual, you’ll see that the 5-button Atomiswave has changed that.

Atomiswave control scheme, described below

The buttons are expected to be laid out like a Capcom six-button cabinet, with the lower right button either not present or not used. The scheme is also laid out like a Capcom fighter, with Light Punch and Strong Punch are next to each other in the top row as buttons 1 and 2, and button 3 (the “extra” button) being used for a new HEAT mode. The bottom row are kicks.

If you map these directly to a Neo Geo pad (with the Select button acting as button 5), you’ll find it’s quite nonsense, and won’t work for the muscle memory at all. So button configuration on Atomiswave games like this is a must-have. Guess I need to replace that battery. This more Street Fighter-like button configuration has now become the standard in King of Fighters, which is one of the reason the MVSX has its bizarre six-button layout.

Booting up

Now Loading, on a black background

One thing that surprised me about King of Fighters Neowave is that it spends nearly 20 seconds loading when you turn it on. This is a one-time thing; I assume it’s copying assets into RAM at bootup once so that it can run the rest of the time without needing to reload them. It’s worth noting that while ROM is faster than a disc, copying data is always going to take time, the more data the more time it’ll take.


As noted, this game is not exactly a port, but is very close to King of Fighters 2002. I found them to play pretty similar. We can directly compare the two: look at the top (KOF2002) and the bottom (KOF Neowave) below.

KOF 2002 gameplay

KOF Neowave gameplay

Neowave mostly uses the extra power of the Atomiswave (which is quite substantial; the Dreamcast can effectively emulate an entire Neo Geo) to give better backgrounds. However, the sprites are pretty much the same. Redrawing all the game’s sprites is quite hard, and it’s one the reasons it took four years between King of Fighters XI and King of Fighters XII. (The other reason is pachinko is more profitable)

But it does amuse me a bit to see differing pixel sizes between the fighters and the background. This is something most modern 2D pixel art games try quite hard to avoid!

15kHz vs 31kHz

You might wonder how that pixel size discrepency works when you move into 15kHz mode. If it’s 240p, after all, that would mean that the background would have the same pixel size, since the Neo Geo is also 240p.

KOF Neowave demonstration gameplay

Unfortunately, look at the telltale text “Demonstration” in the middle of the screen; 15kHz mode in games like this is 480i interlaced video. Still, for the Atomiswave I strongly suggest stasying on 480p; the Framemeister for example will compensate for interlacing with “bob” deinterlacing, which can result in a wiggly picture. If you want to reduce lag, there aren’t that many great options. (Though, the fighters being double-sized means the bobbing effect doesn’t really impact them, which is nice)

The King of Fighters XI

King of Fighters XI installed in the Atomiswave

Swapping Atomiswave cartridges is pretty easy, the off-center connector makes it impossible to get it rotated wrong. It’s nice and practical.


What’s less convenient is that when you change games on the Atomiswave, all your settings are lost. Since it was never designed for multiple games to run simultaneously like the MVS, this makes sense, though it’s a bit of a pain. This can also include your region setting, so make sure to correct that if you’re playing the game outside of Japan.

Standard Sega legal text claiming that the game can't be played outside of Japan

Now, you might be surprised to see “SEGA CORPORATION” at the end of that legal text. Well, as noted, this console was built on Sega technology, and Sega was actually the publisher of King of Fighters XI on the Atomiswave. Sega and Sammy had merged in 2004; while Sammy had been the one to acquire Sega, the amusement arm had consolidated under Sega. (Whereas the Pachinko/Pachislot arm was Sammy’s contribution)

Title screen of KOF XI

King of Fighters XI loads pretty much instantly. It has prematch scenes that my guess are to cover up loading, so it doesn’t need to do as much up-front. This is a much smoother experience; you can really tell that SNK Playmore were starting to get a solid handle on the hardware. These scenes look great with 480p.

Prematch scene in KOF XI, showing a Temple stage upcoming

The gameplay looks a lot like King of Fighters Neowave, with higher-resolution backgrounds but traditional 240p optimized sprites. This can look a little odd when people in the background are rendered at a higher resolution than your fighters in the foreground. Still, once I got into the gameplay I didn’t notice.

KOF XI gameplay, showing a background with people

Unlike Neowave, though, King of Fighters XI uses the “tag-team” battle system from King of Fighters 2003, where you can switch your characters out on the fly, and the battle is one continuous match rather than being divided into rounds. I quite like this system, and this game expands on it quite a bit. However, it’s the last King of Fighters to use it.

Who needs an Atomiswave?

So now you might be thinking, “cool Nicole, I’ll run out and get an Atomiswave, because I want to actually play some of the games that aren’t 2D fighters in the King of Fighters series and you apparently won’t tell me about them”. But what if I told you you didn’t have to? Remember, the Atomiswave uses the same CPU, GPU, and RAM as the Sega Dreamcast. So why can’t I just play my Atomiswave games… on a Dreamcast?

KOF XI on a dreamcast

RetroRGB has a good listing of the games that are available here, but over the past year enthusiasts have realized that Atomiswave games can be ported to the Sega Dreamcast. If you have an optical drive emulator, you can pretty much get a spot-on experience.

I don’t, but even with a burned CD-R, I was impressed. Even the Neowave game-start loading time was only a few seconds slower. (I don’t want to give exact numbers because it’s going to depend on your Dreamcast’s GD-ROM drive, the brand of CD-Rs you use, etc) This really is a spot-on experience, to the point that I have pretty much nothing to show. The games look the same, with just a few things being a bit slower. (For example, the prematch scenes I mentioned in King of Fighters XI)

So if you want to play Atomiswave games and already have a quality Dreamcast setup, why bother with all the hardware? (Of course, make sure to buy Atomiswave games and modify a legal backup copy, of course) Some games have been reported to have graphical glitches, especially running from a CD, but for the fighters at least this is a great option. Unfortunately pirate Atomiswave carts are rampant, so it’s hard to guarantee you’re having a “real hardware” experience even with what looks like a real cartridge.

The end of an era

The Atomiswave really didn’t fail, per se. It had a decent enough run; but it didn’t take the world by storm either. A lot of the “low-end” arcade machine market Sammy was looking for just stopped buying arcade machines instead. Other factors included rampant software piracy, and the aforementioned Sega-Sammy merger: Sega and Sammy had a huge number of arcade platforms, and it made sense to pare them down.

KOF XIII victory scene 'We look and fight exactly the same'

As for the title of this post? This is the last “unique” dedicated arcade hardware the King of Fighters series would see. Following the completion of their deal with Sammy, SNK would switch to Taito’s Type-X hardware, which is essentially a stock PC running a embedded version of Windows, even with upgradeable graphics cards. PC technology surpassed the arcades, so if you want the arcade experience at home, you can often just buy it on Steam.

Never say never, but I suspect the Atomiswave is the newest hardware I’m likely to cover here anytime soon. Still, it’s been fun, especially King of Fighters XI, and I definitely want to get my hands on some of the non-SNK titles. As for the lightgun games, though, I’ll leave those to someone else.

GAME OVER - Thank you for playing