An FPGA cartridge on my MSX, the Franky community tracks, and the return of Xenon 2
It all starts with Ivan's cartridge
A cartridge can be a useful accessory or the start of a new series of experiments. For me, the WonderTANG became both: a way to add memory, storage, and audio to my MSX, but also an opportunity to explore a less common path: that of Sega Master System games. Until I found an old love on my machine: Xenon 2.
The protagonist of this first episode is the version created by Ivan Michelucci, a partner at MSX Italia. I like to tell it starting with the object I have in my hands, because the format of a classic cartridge makes a much more recent technology immediately familiar. Inside, however, is a Sipeed Tang Nano 20K: a small FPGA board that allows you to recreate various digital circuits.
This is a review based on experimentation, rather than a list of specifications. I want to share what piqued my curiosity, where I looked for information, and why playing a game became the guiding thread of my WonderTANG Saga.
[IMAGE PLACEHOLDER 1 — Photograph of Ivan's cartridge next to the MSX]
Ivan Michelucci's WonderTANG in Konami format, the protagonist of these tests.
The origin of the project and Ivan's work
The starting point is the open source WonderTANG project by Luis Felipe Antoniosi, known as Fantoniosi. His work provides hardware, FPGA sources, and documentation: it's the basis for the cartridge I'm using. The availability of the project makes it possible to study it, build it, and reinterpret its physical implementation.
An FPGA isn't simply a processor running an emulation program. The bitstream, the file that configures its logic, defines digital circuits capable of working in parallel. In retrocomputing, this allows the behavior of peripherals and components to be reproduced by connecting them to the real computer.
Ivan started with the WonderTANG V2.0b and reengineered the hardware to fit a Konami cartridge. This involved organizing and reducing the printed circuit board, giving the project a compact form factor that fits into a case familiar to MSX enthusiasts.
The features of Ivan's version are identical to those of the original WonderTANG V2.0b. The merit of its creation lies in the hardware reengineering and format: the cartridge's capabilities derive from Fantoniosi's design and the core loaded into the FPGA. For me, this is an essential distinction, also to correctly attribute each individual's work.
[IMAGE PLACEHOLDER 2 — Ivan's build PCB and Tang Nano 20K detail]
The V2.0b electronics reorganized in Konami format. A photo of the PCB shows Ivan's work.
The functions that I bring into the slot
The microSD, through Nextor, is the most straightforward part to understand: it provides the MSX with convenient mass storage for storing programs and test materials. The 4 MB Memory Mapper adds RAM organized according to the MSX's paging system; the software must, of course, know how to use it.
The 2MB Super MegaRAM SCC+ serves a different role than the Memory Mapper. It provides memory for loading cartridge software and SCC+ functions, with support for various mappers. The OPLL and MSX-MUSIC ROM complete the soundscape, making FM synthesis available to programs that support it.
I'm especially interested in the fact that these capabilities coexist in the same accessory. They're different functions, and knowing their distinction helps understand why a program requires a particular magazine or configuration. Added to this is the Sega Master System VDP with its PSG, implemented in the FPGA for the Franky-compatible environment.
From Supersoniqs and Franky to FPGA
The history of Sega games on MSX dates back to before WonderTANG. With Franky, Supersoniqs brought a hardware expansion to the MSX environment with a VDP compatible with the Sega Master System. This path opened up space for experiments, adaptations, and community-developed tools.
WonderTANG takes over compatibility through the FPGA. This is the connection that interests me: a solution born as a physical expansion continues to live on in a new implementation, and the software work accumulated over the years can still be useful today.
The MSX and Sega Master System share the Z80 processor family, but this doesn't automatically make their games interchangeable. Access to video, audio, controls, and memory depends on the machine's architecture. An SMS ROM may therefore require adaptation and a loader capable of providing the right environment.
In my tests, I ran classic Sega Master System games on the MSX using this feature. I'm fascinated by seeing the actual computer execute the adapted code while the cartridge provides the necessary video hardware. The results must be evaluated on a game-by-game basis: the presence of the Franky core doesn't equate to a promise of universal compatibility.
[IMAGE PLACEHOLDER 3 — Photograph of the MSX station with an SMS game running]
My MSX during testing with the Sega Master System video from WonderTANG.
Xenon 2 and a music that I still carry with me
Of all the games I'd wanted to try, Xenon 2: Megablast held a special place for me. It was my favorite PC game, and I spent a lot of time with it. The ship, the enemies, and the atmosphere of that Bitmap Brothers shooter remain etched in my gaming memories.
And then there's Megablast by Bomb the Bass. That song still rings in my head and I still play it when I DJ at parties with friends. The musical connection to Xenon 2 is part of the reason I wanted to find it on my MSX too.
The game never received an official port for MSX. The option I had was to use the Sega Master System version, specially adapted for Franky. Memories of the PC prompted me to do some research, but the version I ran was the SMS version: graphics, features, and sound should be considered in context, without automatically overlapping with the PC experience.
Searching on the MSX Resource Center
Searching for information, I came across the MSX Resource Center, specifically the discussions dedicated to the Franky projects and the Supersoniq Franky Loader. Reading that material made me realize how much work went into a seemingly simple setup.
Alexito is one of the protagonists of this collective research. His contributions, along with those of GDX and other community members, discuss loaders, patches, and adaptations. Modifying a game also means recognizing which instructions access the peripherals and intervening without confusing code with data: a task that requires knowledge and patience.
It is in this wealth of discussions and software that I found the path to my tests with Xenon 2. For me, the forum was a valuable source of information: the story starts from what I read and recovered, without attributing to the developers any direct collaboration with me that I have not documented.
The patched ROM the loader and the result
I have one concrete certainty from that test: I still have the patched ROM that works, and I booted it with a loader dedicated to the Franky environment. The starting point is the discussion on the Franky Loader. However, I don't remember all the configuration details, the exact name of the executable used, or the command sequence.
I prefer to tell it this way, because turning an incomplete memory into a detailed walkthrough would risk wasting time for anyone wanting to repeat the experiment. The modified ROM and the loader are the core elements of my test; to write a reproducible guide, I'll need to go back to the saved files and verify the original configuration.
I remember the result well, however: Xenon 2 running on my MSX. For a game I'm so fond of, seeing it running on Ivan's cartridge was a particular satisfaction. Behind that screen was the Franky project, the community's work, and the WonderTANG FPGA implementation.
Technically, the game uses the Sega VDP recreated in the FPGA, while the MSX Z80 runs the adapted code. This test interests me precisely because of the way it brings the two systems together. The emotion is personal; the operation is the result of very concrete contributions, spread over several years of experimentation.
[IMAGE PLACEHOLDER 4 — Xenon 2 splash screen and gameplay scene on the real machine]
Xenon 2 running on my MSX through WonderTANG and the software adapted for Franky.
Firmware setup and update
With an FPGA cartridge, even the firmware is part of the experiment. Before programming or updating the WonderTANG, you need to identify the hardware revision and choose the compatible bitstream, following the project documentation. Instructions for a different board should not be automatically transferred to Ivan's V2.0b.
The setup also includes preparing the microSD card and the tools required by the programs I want to use. For these tasks, I find both Fantoniosi's repository and the material from Cristiano Gonçalves, The Retro Hacker, useful, keeping in mind that his build guide documents a previous revision of the card.
In this episode, I'll focus on the context of my tests. A detailed description of the update and configuration should accompany the files, revisions, and verified results: this is the most useful way to move from a personal account to instructions others can follow.
[IMAGE PLACEHOLDER 5 — FPGA configuration or programming screen]
WonderTANG setup. The final screenshot will show the board revision and firmware used.
The thanks behind this screen
I thank Luis Felipe Antoniosi, known as Fantoniosi, for creating and sharing WonderTANG, and Ivan Michelucci for re-engineering V2.0b into the Konami format I used. These two separate efforts, combined, made this adventure possible.
Thanks to Supersoniqs for Franky and for paving the way between MSX and the Sega Master System. Thanks to Alexito, GDX, and the MSX Resource Center community for the patches, loaders, discussions, and shared experiences that helped guide me.
Thanks also to Cristiano Gonçalves, The Retro Hacker, for his documentation and dissemination of the WonderTANG. I'd also like to thank Lorenzo Moretti. And I thank all the enthusiasts who continue to share sources and tests: it's often those details, left in a repository or forum, that spark a new experiment.
The next episode with V9990 and OPL4
Ivan's cartridge gave me a solid starting point: memory, microSD, audio, and a bridge to the world of Sega. Xenon 2 became my gateway to it, with a little research and a lot of curiosity.
In Episode 2, I'll shift my focus to the V9990 and OPL4, the new video and audio capabilities, and testing with the corresponding cores. This also sparks a future goal: attempting to integrate the cores into a single design. Just because they can run separately on the same FPGA doesn't mean they can coexist seamlessly; resources, connections, and timing will be part of the work to be verified.
For now, I'm enjoying Xenon 2 on my MSX. And when I bring Megablast back into a DJ set with friends, that spaceship immediately comes to mind. The WonderTANG Saga continues.
Link for further information
WonderTANG — project and documentation by Fantoniosi
MSX Resource Center — Franky Projects