Revealing Capcom’s Custom Silicon Security

Ask any security professional and they’ll tell you, when an attacker has hardware access it’s game over. You would think this easily applies to arcade games too — the very nature of placing the hardware in the wild means you’ve let all your secrets out. Capcom is the exception to this scenario. They developed their arcade boards to die with their secrets through a “suicide” system. All these decades later we’re beginning to get a clear look at the custom silicon that went into Capcom’s coin-op security.

Alas, this is a “part 1” article and like petulant children, we want all of our presents right now! But have patience, [Eduardo Cruz] over at ArcadeHacker is the storyteller you want to listen to on this topic. He is part of the team that figured out how to “de-suicide” the CP2 protections on old arcade games. We learned of that process last September when the guide was put out. [Eduardo] is now going through all the amazing things they learned while figuring out that process.

These machines — which had numerous titles like Super Street Fighter II and Marvel vs. Capcom — used battery-backed ram to store an encryption key. If someone tampered with the system the key would be lost and the code stored within undecipherable thanks to “two four-round Feistel ciphers with a 64-bit key”. The other scenario is that battery’s shelf life simply expires and the code is also lost. This was the real motivation behind the desuicide project.

An overview of the hardware shows that Capcom employed at least 11 types of custom silicon. As the board revisions became more eloquent, the number of chips dropped, but they continued to employ the trick of supplying each with battery power, hiding the actual location of the encryption key, and even the 68000 processor core itself. There is a 6-pin header that also suicides the boards; this has been a head-scratcher for those doing the reverse engineering. We assume it’s for an optional case-switch, a digital way to ensure you void the warranty for looking under the hood.

Thanks for walking us through this hardware [Eduardo], we can’t wait for the next installment in the series!

IPad Tossed Out For RetroPie Arcade Cabinet Redux

The naming and remixing in this project can get a little confusing to those unfamiliar with the different elements involved, but what [John Gerrard] has done is take a stylish mini arcade cabinet intended as a fancy peripheral for an iPad and turned it into an iPad-free retro arcade gaming cabinet. He also designed his own power controller for graceful startup and shutdown.

The project started with a peripheral called the iCade (originally conceived as a fake product for April Fool’s) and [John] observed it had good remix potential for use as a mini retro gaming cabinet. It was a good starting point: inexpensively purchased off eBay with suitable arcade-style joystick and buttons, a nice layout, and plenty of hacking potential. With a small variety of hardware from familiar sources like eBay and Aliexpress, [John] rounded up most of what he needed.

Continue reading “IPad Tossed Out For RetroPie Arcade Cabinet Redux”

Controlling A Game Room With Amazon Echo

If there are two things we love here at Hackaday, it’s games and automating mundane tasks by adding a lot of electronics and voice control. A game room is, therefore, the perfect sandbox for projects that get us excited in all of the right ways. Liberty Games, a UK-based games room company, already had a really impressive game room (as you might expect). They’ve just posted an awesome build log showcasing how they went about automating mundane game room tasks by adding a lot of electronics and voice control.

There were four tasks that Liberty Games wanted to be able to complete with voice control: releasing billiards balls on their pool table, adding credits to an arcade machine, releasing pinballs on a pinball machine, and control of a CD jukebox. For all of these tasks, they used an Amazon Echo, which already has built-in support for adding new “skills” (Amazon’s term for user-created Alexa commands). These skills allow the Echo to communicate with other devices using JavaScript Object Notation (JSON).

Continue reading “Controlling A Game Room With Amazon Echo”

Put A Pi In Your JAMMA

Most of us who play an occasional arcade game will have never taken a look inside a cabinet however much its contents might interest us. We’ll know in principle what kind of hardware we’d expect to see if we were given the chance, but the details are probably beyond us.

In fact, there is a standard for the wiring in arcade cabinets. Arcade operators demanded running costs as low as possible, and the industry responded with the JAMMA wiring standard. The Japan Amusement Machinery Manufacturers Association was the name the Japanese trade body was known under in the 1980s, and they originated a specification for both wiring and connector that would allow hardware to be easily installed for any game that supported it.

[Jochen Zurborg] has created an interesting board supporting the JAMMA connector, one that interfaces it with a Raspberry Pi and offers full support of the Pi as a video source. He’s launching his Pi2Jamma as a commercial product so sadly there are no schematics or Gerbers for you to look at, but if you’d prefer to roll your own it probably wouldn’t be beyond most Hackaday readers to do so. What it does though is open up the huge world of emulation on the Pi to owners of classic cabinets, and if you don’t mind forking out for one then we can see it might make for a very versatile addition to your cabinet.

We’ve featured [Jochen]’s work before here at Hackaday with a joystick that faithfully replicates arcade items. As to the Pi, this is the first JAMMA board we’ve seen with video, but we’ve featured another board using a Pi to bring console controllers to JAMMA boards in the past.

A Trove Of Arcade Projects

[Ryan Bates] loves arcade games, any arcade games. Which is why you can find claw machines, coin pushers, video games, and more on his website.

We’ve covered his work before with his Venduino project. We also really enjoyed his 3D printed arcade joystick based off the design of a commercial variant. His coin pushing machine could help some us finally live our dream of getting a big win out of the most insidious gambling machine at arcades meant for children.

Speaking of frustrating gambling machines for children, he also built his own claw machine. Nothing like enabling test mode and winning a fluffy teddy bear or an Arduino!

It’s quite a large site and there’s good content hidden in nooks and crannys, so explore. He also sells kits, but it’s well balanced against a lot of open source files if you’d like to do it yourself. If you’re wondering how he gets it all done, his energy drink review might provide a clue.

Classing Up A RetroPie Arcade With A Wine Barrel

Arcade cabinets are a lot of fun, and something most of us would probably like in our homes. Unfortunately, space and decor constraints often make them impractical. Or, at least, that’s what our significant others tell us. Surely there must be a workaround, right?

Right! In this case, the workaround [sid981] came up with was to build a RetroPie arcade into a fancy looking wine barrel. The electronics are pretty much what you’d expect for a RetroPie system, and the screen is set into the top of the barrel. Control is handled by a wireless controller that can be tucked away when it’s not in use, and a glass top simultaneously protects the screen and lets guests use the barrel as a bar table.

Continue reading “Classing Up A RetroPie Arcade With A Wine Barrel”

Desuiciding Capcom Arcade Boards

Capcom’s CPS2 – or CP System II – was the early to mid-90s arcade hardware famous for Super Street Fighter II, Alien vs. Predator, and a few of the Marvel and Capcom crossover arcade games. As you would expect, these boards have become collectors items. Unfortunately for future generations, Capcom took some short-sighted security measures to prevent copying the games, and the boards have been failing over the last two decades.

After months of work, [ArcadeHacker] and several other arcade enthusiasts have reverse engineered the security protocol and devised a method of de-suiciding these arcade boards, allowing for the preservation of this hardware and these games. The code that does the trick is up on GitHub.

Last year, [ArcadeHacker] reverse engineered the on-chip security for Capcom’s Kabuki processor, the CPU used in some of Capcom’s earlier arcade boards. It used a similar protection scheme. In the Kabuki hardware, the on-chip ROM was interspersed with a few XOR gates on the processor’s bus. With a security key kept in battery-backed memory, this was enough to keep the code for the game secret, albeit at the cost of preventing historical preservation.

Over the next few weeks, [ArcadeHacker] will post more detailed information about the copy protection scheme of the CPS2 board, but the proof-of-concept works right now. It’s now possible to revive a CPS2 board that has killed itself due to a dead battery, and the hardware is as simple as an Arduino and a few test clips. You can check out a video of the exploit in action below.

Continue reading “Desuiciding Capcom Arcade Boards”