For $5, [William] of Toronto’s Hacklab hackerspace got a hold of one of the smallest CRT screens ever made – about the size of a large coin. Over the course of a couple sessions – including a public hack boothside at their Mini Makerfaire – [William], [Igor], and several other members managed to connect it as a monitor directly off a Raspberry Pi. The end-goal is the world’s smallest MAME cabinet (smaller by almost half than this LCD one).
As Canada followed the US and stopped broadcasting analog back in 2011, it became quite a challenge to feed the screen a video source. They disclosed early that the easiest solution would just be an RF transmitter on the Pi and then tune the micro-set to that channel. Too easy. They wanted something elegant and challenging so they went digging into the circuitry to find a place to insert a composite video signal directly.
The real story here is their persistence at reverse engineering. The PCB was folded like a cardboard box to fit in the original case, making large portions of the circuitboard and wiring inaccessible. Even when they managed to trace the signal to what they thought was the appropriate chip (marked C80580), they could not find any information on the 30 year old chip. Noting that every other chip on the board was Panasonic and started with “AN5”, [Igor] suspected the mystery silicon was just renamed and went through every single datasheet he could find with that prefix. Combined with form factor, pin count and purpose, his sleuthing was rewarded with a guess for a match – the AN5715. His hunch was correct – using that datasheet led him to the answers they required.
Then they just had to figure out how get the composite signal the Pi outputted into something the chip would use to display the correct image. There were no shortage of challenges, failures and dead ends here either, but they had help from the rest of their membership.
Their project log is an interesting narrative through the process and in the end of course, it worked. It is displayed beautifully with a clear acrylic case and ready for a cabinet to be built.
Building a MAME machine around a Raspberry Pi has been the standard build for years now, and tiny versions of full-sized arcade machines have gone from curiosity to commonplace. [
The entire enclosure is 3D printed, and most of the electronics are exactly what you would expect: A Raspberry Pi, 2.5″ LCD, and a battery-powered speaker takes up most of the BOM. Where this build gets interesting is the buttons and joystick: after what we’re sure was a crazy amount of googling, [diygizmo] found something that looks like a normal arcade joystick, only smaller. Unable to find a suitable replacement for arcade buttons, [diygizmo] just printed their own, tucked a tact switch behind the plastic, and wired everything up.
Add in some decals, paint, and the same techniques used to create plastic model miniatures, and you have a perfect representation of a miniature arcade machine.
Back in the day, and by that we mean the late 80s and early 90s, arcade machines started using the JAMMA standard, a means for a single arcade board to be wired in to the controllers, video output, and other ephemera found in arcade cabinets. Since then, quite a few people have amassed a collection of these vintage arcade boards. Putting them to use requires a means of providing power, video output and controller connections. The usual way of wiring in a joystick and buttons is with a wiring harness, but [Mike] and [Jasen] are connecting Xbox 360 and PS3 controllers to their machines with the help of a Raspberry Pi Hat.
[Mike] and [Jasen] created Project Kajitsu to replace the expensive ‘Supergun’ controllers arcade game collectors usually use to play Street Fighter, X-Men, and Battletoads. They’re using the USB ports on a Raspberry Pi B+ to listen to two XBox or PS3 controllers and translate button mashing into something these old games can understand.
The guys are using a custom Linux Kernel that boots in just a few seconds, providing the bare minimum of an OS to support the controllers. The board itself is extremely simple; just a few bus transceivers, caps, resistors, and headers. They have an iPhone-quality vertical video proof of concept video (below), and although they’re still figuring out the best way to simplify the Bluetooth pairing process, they’re well on their way to supporting wireless controllers.
This board only provides controller input. If you have one of these old boards, you will need video output. That’s another project entirely, but very simple if you have an SCART monitor.
Continue reading “Console Controllers for JAMMA Boards”
Are you the mutant savior? Are you prepared for the robot uprising of 2084? Have you accepted robotron into your life? The Church of Robotron is now conducting training, testing, and confession at the new window altar in downtown Portland.
The Church of Robotron is the
fake totally legit religion based on the classic arcade game prophecy Robotron 2084. In keeping with the church’s views on community outreach and missionary work, a Robotron altar has been installed at the Diode Gallery for electronic arts.
The altar consists of a system running Robotron 2084 with capacitive sensing controls built by DorkbotPDX’s own [Phillip Odom]. He’s using the same techniques featured in his capacitive sensing workshop, allowing the game to be played 24 hours a day. There are also monitors displaying the leaderboard and tenants of the Church of Robotron.
The Church of Robotron has also been showing up at Toorcamp for a few years now, with an even more spectacular altar that triggers physical events in response to game events. That’s a very cool use of MAME’s debugger, and a story worthy of its own Hackaday post.
Video of the altar below.
Continue reading “Repent! The Church of Robotron Accepts All!”
Once upon a time, arcades were all the rage. You could head down to your local arcade with a pocket full of quarters and try many different games. These days, video arcades are less popular. As a result, many old arcade games are becoming increasingly difficult to find. They are almost like the artifacts of an ancient age. They are slowly left to rot and are often lost or forgotten with time. Enter, MAME.
MAME (Multiple Arcade Machine Emulator) is a software project, the goal of which is to protect gaming history by preventing these arcade machines from being lost or forgotten. The MAME emulator currently supports over 7000 titles, but there are still more out there that require preservation. The hackers who work on preserving these games are like the digital Indiana Jones of the world. They learn about lost games and seek them out for preservation. In some cases, they must circumvent security measures in order to accurately preserve content. Nothing as scary as giant rolling boulders or poison darts, but security nonetheless.
Many of the arcade cabinets produced by a publisher called NMK used a particular sound processor labeled, “NMK004”. This chip contains both a protected internal code ROM and an unprotected external ROM that controls the sound hardware. The actual music data is stored on a separate unprotected EEPROM and is different for each game. The system reads the music data from the EEPROM and then processes it using the secret data inside the NMK004.
The security in place around the internal ROM has prevented hackers from dumping its contents for all this time. The result is that NMK games using this chip have poorly emulated sound when played using MAME, since no one knows exactly how the original chip processed audio. [trap15] found it ridiculous that after 20 years, no one had attempted to circumvent the security and dump the ROM. He took matters into his own hands.
The full story is a bit long and contains several twists and turns, but its well worth the read. The condensed version is that after a lot of trial and error and after writing many custom tools, [trap15] was able to finally dump the ROM. He was able to accomplish this using a very clever trick, speculated by others but never before attempted on this hardware. [trap15] exploited a vulnerability found in the unprotected external ROM in order to trick the system into playing back the protected internal ROM as though it were the sound data stored on the EEPROM. The system would read through the internal ROM as though it were a song and play it out through the speakers. [trap15] recorded the resulting audio back into his PC as a WAV file. He then had to write a custom tool to decode the WAV file back into usable data.
[trap15] has released all of his tools with documentation so other hackers can use them for their own adventures into hardware hacking. The project was a long time in the making and it’s a great example of reverse engineering and perseverance.
[Greg] wanted to build a MAME cabinet. Not one of those monsters that take up a bunch of floor space, mind you: this one would be table-top size. He admits he could have made his game system out of new, currently available, off the shelf parts, but part of the design goal was to reuse old hardware that was kicking around. It was important to [Greg] to keep unnecessary waste out of the landfill.
An old PC motherboard was pulled out of an old desktop. It’s not fast enough for use as an everyday computer but it will be totally sufficient for a MAME machine. The project’s screen is an old 13 inch Gateway CRT computer monitor. Notice that it is turned 90 degrees so that it is taller than it is wide. This screen orientation lends itself better to certain types of games. The monitor’s plastic casing was removed before some measurements were taken. SketchUp was used to plan a basic idea of the cabinet.
The controls consist of a joystick and 4 buttons. During past projects, [Greg] has had experience with the least-expensive arcade controls available on eBay. Well, you get what you pay for. This time around he ponied up the extra cash for some high quality controls and is satisfied with the purchase. These buttons were wired straight into a PS/2 keyboard so the computer does not know the difference between the keyboard keys or recently added controls… another great re-use of old obsolete hardware.
The cabinet is made from MDF, glued and screwed together. The limited wood working tools available wasn’t a show stopper for this dedicated builder. For example, the square hole for the joystick was made by removing most of the material with a spade drill bit before using a chisel to clean up the edges. Doing it this way was a little tedious, but you have to do what you have to do sometimes. Once the entire cabinet was finished, several coats of paint were added in a yellow and blue water-theme. Black rubber molding finishes off the edges of the cabinet nicely.
A ton of people sent in this video of crazy Russians who have taken a microwave, removed the magnetron, taped it to a broom, and turned it on. Don’t try this at home. Or near us.
You know the Google Cardboard kit that’s a real VR headset made of cardboard (and a smart phone)? Google may have gotten their inspiration from Oculus, because every Oculus Rift DK2 ships with a Samsung Galaxy Note 3 inside.
Ever design a PCB and be disappointed by the quality of the silkscreen? [Paul Allen] has been defining the edges of his PCB labels with the copper layer, and the examples are dramatic. Etching copper is what you actually pay for when you fab a board, so it should come as no surprise that the quality is a little higher.
Dunk tanks are fun, but how about competitive dunk tanks? [Chad] built a dunk tank (really more of a ‘dunk shower’) out of a 2×4 tripod, a garbage can, and a few parts from a the toilet aisle of Home Depot’s plumbing department. Then he built a second. Set up both dunk showers across from each other, give two people a few balls, and see who gets soaked last. Looks fun.
Want a MAME cabinet, but don’t want it taking up room in your house? Build a MAME coffee table! Here’s the reddit thread. Maybe we’re old-fashioned, but we’d rather have a giant NES controller coffee table.
Last week we saw a 16-bobbin rope braiding machine, but odd braiding machines like this aren’t limited to fibers. Here’s a wire twisting machine for making RS422 cables. It only produces a single twisted pair, but that’s really all you need to create a cable. Somebody get some paracord and make some Cat5.