Reverse Engineering The SEGA Mega Drive

January 19, 2022 by Bryan Cockfield 16 Comments

With the widespread adoption of emulators, almost anyone can start playing video games from bygone eras. Some systems are even capable of supporting homebrew games, with several having active communities that are still creating new games even decades later. This ease of programming for non-PC platforms wasn’t always so easy, though. If you wanted to develop games on a now-antique console when it was still relatively new, you had to jump through a lot of hoops. [Tore] shows us how it would have been done with his Sega Mega Drive development kit that he built from scratch.

While [Tore] had an Atari ST, he wanted to do something a little more cutting edge and at the time there was nothing better than the Mega Drive (or the Genesis as it was known in North America). It had a number of features that lent the platform to development, namely the Motorola 68000 chip that was very common for the time and as a result had plenty of documentation available. He still needed to do quite a bit of reverse engineering of the system to get a proper dev board running, though, starting with figuring out how the cartridge system worked. He was able to build a memory bank that functioned as a re-writable game cartridge.

With the hard parts out of the way [Tore] set about building the glue logic, the startup firmware which interfaced with his Atari ST, and then of course wiring it all together. He was eventually able to get far enough along to send programs to the Mega Drive that would allow him to control sprites on a screen with the controller, but unfortunately he was interrupted before he could develop any complete games. The amount of research and work to get this far is incredible, though, and there may be some helpful nuggets for anyone in the homebrew Mega Drive community today. If you don’t want to get this deep into the Mega Drive hardware, though, you can build a cartridge that allows for development on native Sega hardware instead.

The Dreamcast Legacy

December 22, 2021 by Matthew Carlson 48 Comments

The Dreamcast is a bit of an odd beast. Coming on the heels of the unpopular Sega Saturn, the Dreamcast was meant to be a simple console built with off-the-shelf parts and released in late 1998. The Nintendo 64 was already tough competition (1996). Ultimately, the Dreamcast fell out of the public eye in the early 2000s as the Playstation 2, Xbox, and Gamecube were all released with incredible fanfare just a few years later. In some sense, Sega’s last console is a footnote in gaming history.

But despite not achieving the success that Sega hoped for, the Dreamcast has formed a small cult following, because as we know, nothing builds a cult-like following like an untimely demise. Since its release, it has gained a reputation for being ahead of its time. It was the first console to include a modem for network play and an easy storage solution for transferring game data between consoles via the VMUs that docked in the controllers. It had innovative and classic games such as Crazy Taxi, Jet Set Radio, Phantasy Star Online, and Shenmue. Microsoft even released a version of Windows CE with DirectX allowing developers to port PC games to the console quickly.

We see our fair share of console hacks here on Hackaday, but what is the ultimate legacy of the Dreamcast? How did it come to be? What happened to it, and why did so much of Sega’s hopes ride on it? Continue reading “The Dreamcast Legacy” →

Two-Player PVC Racing Rig Plays Daytona USA

May 1, 2021 by Lewin Day 9 Comments

SEGA’s Daytona USA is that big orange arcade racing machine you remember from the 90s that still seems to hang on in cinemas and pizza joints worldwide. Its controls may be floaty and physics unrealistic, but it’s probably the one racing game that almost everyone has played at one point or other. [Tom Tilley] decided to build a PVC racing rig for the game during his travels in Thailand.

As a bonus, the lightweight rigs can be broken up and transported easily by scooter.

PVC pipe is used to whip up the frames for the budget simulator, inside which each player sits. Different sizes of PVC pipe and various adapters are used to create a basic steering wheel, to which a potentiometer is attached, while the centering mechanism is simply a rubber band. The pedals are built similarly and fitted with microswitches. The build relies on a cheap USB gamepad that mimics the typical PlayStation Dual Shock design, with the pot and switches wired in place of the existing thumbstick and buttons. A computer running the PC version of Daytona USA is then used to complete the setup, along with a projector for split-screen fun.

It’s certainly not a high-end simulator by any means, but for the price of some pipes and cheap controllers, [Tom] was able to create a two-player racing rig for a fraction of the cost to hire the real arcade machine for a weekend. The kids that playtested the system certainly seemed to have a good time, as well. We’ve seen similar low-tech builds before, too – with impressive results. Video after the break.

Continue reading “Two-Player PVC Racing Rig Plays Daytona USA” →

Restored Dreamcast Is A SEGA Fan’s Dream Come True

February 11, 2021 by Tom Nardi 43 Comments

[Bren Sutton] has been a long time fan of SEGA’s Dreamcast, eagerly snapping one up right around its October 1999 European release. But after years of neglect and a somewhat questionable paint job a decade or so back, he decided it was time to spruce his old friend up. He could have just cleaned the machine and been done with it, but he took the opportunity to revamp the console’s internals with both practical and cosmetic trickery.

The first step was getting the system looking a bit fresher. Removing the silver metallic paint he applied in his youth with a rattle can wasn’t going so well, so he ended up buying a broken donor console on eBay so he’d have a new shell to work with. The donor was yellowed with age, but a coating of peroxide cream and a few hours under a cheap UV light got it whitened up nicely. Now that he had a fresh new case, [Bren] turned his attention to the internal components.

Those who might be plugged into the active Dreamcast homebrew scene may already know that several upgrade modules exist for SEGA’s last home game console. One of the most popular replaces the optical drive with an SD card filled with your favorite game ISOs. You can also get a modern high efficiency power supply, as well as a board that replaces the original soldered-on clock battery with a slot that fits a CR2032. [Bren] threw them all in, ensuring several more years of gaming bliss.

But he wasn’t done yet. He also wanted to add some visual flair to his new and improved console. After some consideration, he gingerly cut the logo out of the Dreamcast’s lid, and installed an Adafruit CLUE board underneath it. With a few carefully crafted GIFs installed onto the CircuitPython-powered board, the console now has a gorgeous fully animated logo that you can see in the video after the break.

[Bren] could have really taken his console to the next level by doubling its available RAM to an eye-watering 32 MB, but considering the limited software support for that particularly bodacious modification, we’ll let it slide. Continue reading “Restored Dreamcast Is A SEGA Fan’s Dream Come True” →

Double The RAM Of A Dreamcast Console For A Cool 32 MB

June 26, 2020 by Jenny List 32 Comments

The Sega Dreamcast is the forgotten orphan of the console wars, an extremely capable machine never able to escape the shadow of its PlayStation rivals and because it marked the end of Sega’s console line, never redeemed in reputation by a more popular successor. It retains a significant following a couple of decades after its heyday though, and still sees hardware hacks such as [Tsowell]’s doubling of its available RAM to 32 MB.

The console shipped with 16 MB of memory in two banks, but while the SH4 processor can address twice that figure the designers at Sega never brought the required address line out from under the BGA. So it should be impossible to give it a memory expansion, but when hardware hackers are at work nothing should be ruled out. The hack involves manipulation of the bank switching addressing, and took several careful readings for us to fully understand. The new RAM chips have two address lines tied together and wired to another, a job for some fine but ultimately not impossible soldering. To take advantage of the extra RAM there are a set of patched BIOS images.

So, if you either have a spare Dreamcast you care little enough about to risk, or you consider your console hacking skills to be so advanced that it will be a piece of cake, you can now double the platform’s RAM. Extra points if you also make it portable.

Thanks [John Little] for the tip.

Header: Evan-Amos / CC BY-SA 3.0

An Open Hardware Sega Genesis Cartridge Dumper

May 5, 2020 by Tom Nardi 25 Comments

You might be wondering why anyone would build device to dump Sega Genesis and Mega Drive cartridges. Perhaps they want to play their well-worn copy of The Lost Vikings on their phone, or they want to keep their QVC Limited Edition Maximum Carnage box set in near mint condition. Maybe. But we’re betting that [tonyp7] was just looking for a challenge, and as an added bonus, the world gets another cool open hardware gadget in the process. Sounds like a good deal to us.

Based on the ATmega324PB, the GenDumper can take those dusty old Sega cartridges and back them up to an image file on your computer. Right now the hardware depends on a Windows program, but according to the documentation, [tonyp7] is working on a platform-agnostic Python script so everyone can play along. What you do with the image file after you’ve dumped it is your business, but presumably loading it up in an emulator would be the next step.

Considering how easy it is to find ROMs for these old games online, do you actually need a GenDumper of your own? Probably not. But it’s still an interesting piece of hardware, and if you look close enough, you just might learn a thing or two from the design. For example, [tonyp7] shows how a relatively easy to work with 12 pin USB-C connector can be used on your USB 2.0 projects to embrace the new physical connector without diving into a full USB 3.0 implementation. The keen-eyed reader might also note there’s a lesson to be learned about finalizing the name of your project before sending off your PCBs for manufacturing.

A perusal of the archive uncovered a similar project from 2012 that, believe it or not, was also tested on a copy of Madden 96. Whether that means the game is so beloved that hackers want to make sure its preserved for future generations, or so despised that they are secretly hoping the magic smoke leaks out during testing, we can’t say.

Thea Flowers – Creating A Sega-Inspired Hardware Synthesizer From The Ground Up

November 22, 2019 by Lewin Day 5 Comments

For those who grew up with video games, the legendary sounds of consoles past are an instant nostalgia hit. [Thea Flowers] first got her hands on a gamepad playing Sonic the Hedgehog, so the sounds of the Sega Genesis hold a special place in her heart. Decades later, this inspired the creation of Genesynth, a hardware synth inspired by the classic console. The journey of developing this hardware formed the basis of [Thea]’s enlightening Supercon talk.

[Thea’s] first begins by exploring why the Genesis sound is so unique. The Sega console slotted neatly into a time period where the company sought to do something more than simple subtractive synthesis, but before it was possible to use full-waveform audio at an affordable price point. In collaboration with Yamaha, the YM2612 FM synthesis chip was built, a cost-reduced sound engine similar to that in the famous DX7 synthesizer of the 1980s. This gave the Genesis abilities far beyond the basic bleeps and bloops of other consoles at the time, and [Thea] decided it simply had to be built into a dedicated hardware synth.

Continue reading “Thea Flowers – Creating A Sega-Inspired Hardware Synthesizer From The Ground Up” →