Coin Acceptors Are Higher-Tech Than You Think

April 10, 2022 by Al Williams 16 Comments

Coin-operated machines have a longer history than you might think. Ancient temples used them to dispense, for example, holy water to the faithful in return for their coins. Old payphones rang a bell when you inserted a coin so the operator knew you paid. Old pinball machines had a wire to catch things with holes in the middle so you couldn’t play with washers. But like everything else, coin acceptors have advanced quite a bit. [Electronoobs] shows a unit that can accept coins from different countries and it is surprisingly complex inside. He used what he learned from the teardown to build his own Arduino-based version.

For scale, there is the obligatory banana. Inside the box there are several induction coils and some photo electronics. In particular, there are two optical sensors that watch the coin roll down a ramp. This produces two pulses. The width of the pulse indicates the diameter of the coin, and the time between the pulses tells its speed.

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Brain Transplant Makes One Arcade Machine Play Games From Another

April 26, 2020 by Jenny List 1 Comment

We’re used to games consoles in which the same hardware plays a variety of different games, but if we were to peer inside arcade cabinets of an older vintage we’d find custom boards unique to every game. Some boards from the same manufacturers shared common hardware traits even if they weren’t identical though, and [twistedsymphony] has taken advantage of this to make one vintage Taito game — Gun & Frontier — run on the hardware for another, Ah Eikou no Koshien. It’s a fascinating tale across a forum thread, that’s well worth a read even if you will never touch a vintage arcade board.

We might expect that the tool of choice would be a logic analyser or similar, but unexpectedly the solution to this hack was found in MAME. The arcade emulator conceals a wealth of information about these boards, from which you can discover their differences and try out possible solutions. The hardware hacks are surprisingly straightforward, a few bodge wires and an extra address line for a larger ROM. A programmable logic array required dumping and rewriting to fix a graphics corruption issue and a little bit of ROM tweaking after emulating a controller problem in MAME was required, but it seems that yes, one game can run on another. Certainly less painful than the Taito hack that required a chip to be decapped.

[via r/ReverseEngineering]

Jackpot!: The Trials And Tribulations Of Turning A Slot Machine Into An ATM

November 21, 2019 by Danie Conradie 15 Comments

Have you ever wished that slot machines dispensed money as easily as an ATM? Well so did [Scotty Allen] from Strange Parts, so in collaboration with his friend [Matt] decided to combine the two. After a four-month journey fraught with magic smoke and frustration, they managed to build a fully functional ATM slot machine.

The basic idea is that you insert your card and enter your pin like on a normal ATM, select your winning amount, and pull the lever. This sets wheels spinning, which come to a stop with three-of-a-kind every time, and you win your own money as a bucket load of coins with all the accompanying fanfare. The project took way longer than [Scotty] expected, and he ended up missing his original deadline to show off the machine at DEF CON.

They started with an old broken Japanese slot machine, and replaced the control board with an Arduino Due after a lot of reverse engineering and hacking. [Scotty] did a cool video just on getting the original vacuum fluorescent display working. Integrating the ATM parts proved to be the biggest challenge, with number of very expensive parts releasing their magic smoke or getting bricked in the process. [Scotty] came up with an ingeniously simple hack to interface the ATM hardware with the Arduino. The cash note dispenser uses multiple sensors to detect if there are notes loaded and if one is successfully dispensed. These were spoofed by the Arduino, which controls two coin hoppers instead to dispense appropriate amount of quarters or pennies. The build was rounded off with some very neat custom graphics on the glass panels, and the machine was finally showed off at a local arcade.

This was an awesome project, and we can appreciate the fact that [Scotty] made no attempt to hide the real emotional roller coaster that anyone who has worked on a large project knows, but is rarely documented in logs. [Scotty] has made a name for himself by building his own iPhone from parts and touring Shenzhen’s many factories. Check out the videos after the break Continue reading “Jackpot!: The Trials And Tribulations Of Turning A Slot Machine Into An ATM” →

Revealing Capcom’s Custom Silicon Security

April 3, 2017 by Mike Szczys 52 Comments

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!

Marvin’s Marvelous Mechanical Museum

July 17, 2014 by Mike Szczys 9 Comments

Don’t call it an arcade. There are arcade-like things about it… like dance-based video games, Skee-ball, and tickets — oh so many tickets. But Marvin’s Marvelous Mechanical Museum is a one-of-a-kind that you need to visit next time you’re in the North suburbs of Detroit, Michigan.

[Marvin] was there in person, as he is many days. He talked with us for a few minutes and we’ve folded his interview, along with footage of many of the attractions, into the video above.

He’s been collecting for more than three decades. The attractions are packed into every bit of floor space, spilling up onto the walls, and hanging from every spot in the ceiling. There are true antiques from both home and abroad that could be referred to as automatons, rows of fortune tellers, a track of large airplane models that make a loop around the establishment when fed a quarter, and much more.

Some of the attractions were build for him, like the robot band you can make out behind [Marvin] during the interview. It is a MIDI-based build that allows songs to be selected from a touchscreen. Soon to be on exhibit is a Tesla-coil-based offering which [Marvin] commissioned after taking second place to [Nicolai Tesla] on a list of oddest museums.

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How The Mazes Were Generated For Classic Berzerk Game

July 21, 2013 by Mike Szczys 16 Comments

berzerk-random-maze

This is a screenshot from the Atari 5200 version of the classic game Berserk. But the write-up we’re featuring actually looks at the original coin-op version. The maze for each level was established on the fly using a seed number fed into a rudimentary algorithm . Here’s a close look at how the maze building code actually worked.

Recently we saw a talk by Pitfall creator [David Crane] as part of our Retrotechtacular series. That is a real gem of programming history, and one of our favorite take-aways was that the levels were not hardcoded, but built using a random number generator algorithm with a hardcoded seed (so that the game was the same each time you played it). This uses a similar method but with a somewhat random seed.

The maze building was reverse engineered by observing the game in a MAME emulator, and by digging through disassembled code. Each time the code is “cold started” the seed starts out at zero, but from there the room number is used as the next seed. This is fed through a very simple algorithm. It generates directions for the walls, which use s few bit-wise operations to add the pillars inside the rooms.

It’s a great thing to study if you’re writing games for your embedded projects. By generating the room programmatically you don’t use up as much program memory. Of course these days even simple hobby controllers have way more storage to work with than [Alan McNeil] had when he designed Berserk.

[via Reddit]

[Image Source]

NES Zapper Modified To Work With An Old Nintendo VS. Cabinet

June 6, 2013 by Mike Szczys 12 Comments

nes-zapper-nintendo-vs

The company which [Eric Wright] works for recently bought a Nintendo VS. It had Ice Climber installed as one of the titles but they asked the vendor if it was possible to swap it out for the Duck Hunt ROM. They had the ROM but not a light gun that would work with the system. [Eric] suggested they buy it with Duck Hunt and hack an NES Zapper to work with the VS cabinet.

Let’s take a step back for a moment. The Nintendo VS was a coin-operated gaming cabinet you would find in an Arcade. Luckily there’s quite a bit of information about the original hardware on the web. Some research helped him discover that electronically the only difference between the arcade and home versions of the Zapper is that the sensor capture is inverted. This was fixed by replacing a transistor in the gun with a jumper wire. The next challenge was figuring out how to wire the gun up to the second controller port. And finally he patched the ROM to work with the incorrect PPU as the right chip was not easily sourced.

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