A 1986 Panasonic FS-A1—a Japanese MSX2 home computer—pulling a game down off the open internet, with no cartridge in the slot and nothing feeding it but power and WiFi. I soldered the little board that makes it possible; I did not invent the wizardry running on it, and I'm cheerfully a step behind the people who did. This is the start of that story, told from the cheap seats.
Most of what comes out of this workshop is me fixing or building something I already half understand. This one was different, and it's the kind of project I like best: I jumped into a corner of the hobby I knew almost nothing about. Soldering the board together, I was fine—a hot iron is home turf. But the firmware side, the flashing and the config files and the command-line incantations, was genuinely new ground, and I leaned on every tool I could find to muddle through. That's the real job in here, more than any cartridge I sell or repair I make: learning something new out loud and trying to pass the spark along. If you've ever wanted to poke at something well outside your lane, this series is for you, because I spent most of it outside mine.
The machine is a Panasonic FS-A1: a 1986 MSX2, sold mostly in Japan, a compact black home computer that loaded its software from cartridges and cassette tapes. I own this one and a Sony HitBit that's boxed away, and that's the whole MSX collection. Forty years on, the FS-A1 is pulling games down over my home WiFi. No tapes, no cartridges—a little adapter in the cartridge slot and a wireless router across the room.
That adapter is a FujiNet, and getting one talking to the MSX took me on a genuine adventure—a stubborn boot screen, a fix that brought the games back for reasons I still can't fully explain, and a microSD card that, it turned out, half the people doing this had trouble with too. None of that was the project's fault. Most of it was me, learning. This first post is the gentle part: what the MSX is, what FujiNet is, and what's actually on the little board. The next two are where I get in over my head.
What an MSX is, quickly
MSX wasn't one company's computer—it was a 1983 standard, the way VHS was a standard for tape. A bunch of manufacturers (Sony, Panasonic, Sanyo, Toshiba and more) all built machines to it, so software from one would generally run on another. It never caught on much in the United States, but it was huge in Japan, and big in parts of Europe and South America. The FS-A1 is Panasonic's take: an MSX2, a little more capable than the original, with a built-in software suite the moment you switch it on.
The important part for this story: an MSX loads software through a cartridge slot, and—depending on the machine—from cassette tape or a floppy disk drive too. The FS-A1 takes cartridges and tape. Either way, the cartridge slot is the main front door, and that's the one FujiNet comes in through.
What FujiNet is (and who actually made it)
FujiNet is the clever bit, and I want to be careful here, because it isn't mine to explain with any authority. Plainly: vintage machines like this have no concept of the modern internet—no TCP/IP, no WiFi, nothing that knows what a web server is. FujiNet is a small WiFi device that handles all of that for the old computer and hands it back results in a form 1980s hardware already understands. On this MSX setup the machine thinks it's reading from a cartridge in its slot; FujiNet is quietly fetching files off the internet on its behalf.
It started on the Atari 8-bit and has spread across a whole shelf of vintage systems since. It's an open-source effort that began with Thom Cherryhomes—who had the idea of giving every old home computer a path onto the modern internet, and still leads the firmware today—and has grown into a large, active community far more capable than me, generous with a hobbyist hanging around their Discord asking beginner questions. I've been following along for a while, mostly from the sidelines, and the MSX support is one of the newer, still-in-progress corners of the project. That matters for this story: I wasn't installing a finished product, I was tagging along on something being actively brought up, rough edges and all.
How I got pulled in (a Chicago thing)
I didn't find this project cold off the internet—I got pulled into it locally, which feels exactly right for where I sit. One of the FujiNet developers, who goes by nwah, is a fellow member of SCAT, the Suburban Chicago Atarians, the local Atari club I belong to. His work, and his enthusiasm, are a big part of why I'm here at all.
That's less of a coincidence than it sounds. Chicago has a deep, stubborn retro-computing streak—the right overlap of tech, old manufacturing muscle, and the kind of spunk it takes to keep forty-year-old machines alive. Vintage Computer Festival Midwest, the Midwest's largest, draws a couple thousand people to Schaumburg every year, practically in my backyard. A project like this reaching my bench through someone from the local club is just how it tends to work around here.
Two computers on one board: the ESP32-S3 WiFi chip (left) and the Raspberry Pi Pico RP2350 (the cartridge impersonator) that plugs into the MSX bus.
What's actually on the board
Here's the part I think is genuinely cool. The hardware I'm running is a prototype board by FozzTexx, and it isn't really an "MSX board" at all—it's a universal one. The project is even named for it: FujiVersal. There's a main development board carrying the two brains, plus a broken-out, ISA-style bus, and then a small machine-specific adapter clips on to fit whatever cartridge-slot computer you're pointing it at. Mine has the MSX adapter on it. Swap the adapter, and in principle the same board goes after a different vintage machine. One board, many targets.
The two brains:
- An ESP32-S3—the WiFi side. This is the chip that gets on my network and talks to the internet.
- A Raspberry Pi Pico (an RP2350)—the impersonator. Running the FujiVersal firmware, it sits on the computer's bus and pretends to be a ROM chip, feeding the MSX data as if a cartridge were plugged in. (FozzTexx's own description: it "emulates the signals of a ROM chip and talks on the CPU bus.")
The two talk to each other over a short USB link—the ESP32 fetches from the internet, the Pico hands it to the MSX. And the MSX target is still in bringup—the early stage where a new machine's support is being shaken out—so "made possible with support from viewers like you" is literally printed on the board. I'm running someone's prototype, in progress, and honestly that's part of the fun.
The flashing, and the tools I used to get through it
Here's where I'll be straight, because it's half the point. The soldering I had handled; the flashing—getting firmware onto the two chips, editing config files, running commands I'd never seen—was the part I was learning as I went. So I used the tools available to me, and to anyone: I had Claude Code, inside Visual Studio Code, walk me through it. I don't shy away from that. It wasn't push-button magic, either—there was real back-and-forth, a little sparring, a few wrong turns—but between the assistant handling the parts I couldn't and me slowly working out what was actually happening underneath, we got there in the end. For the FujiNet folks these are trivial commands. For me it was an education. And that's the part I find genuinely exciting: someone with more curiosity than credentials can reach further than they used to now, as long as they stay honest about what they know and what they don't.
The payoff, teased: a MegaROM game running on the FS-A1, pulled straight off the internet. Full story in Part 3.
Where this series goes
Three Bench Notes on the MSX FujiNet build:
- Part 1 (this post): what the MSX and FujiNet are, what's on the board, and why I'm cheerfully out of my depth.
- Part 2: the climb—the boot screen that kept winning, a fix that cost me an evening and that I still can't fully explain, and the microSD card that turned out to be a shared headache rather than my mistake.
- Part 3: the payoff—big "MegaROM" games coming down over WiFi, a fix nwah rolled into the firmware so I could play them without the SD card at all, and the moment a developer's logo came up on a forty-year-old screen and I put both hands in the air.
What I learned (so far)
Three things, before the real work starts in Part 2. The gap I expected was backwards: putting the board together was the comfortable part, and the firmware was where I had to slow down and actually learn. The fastest way into something like this isn't a tutorial—it's a person; I'm here because someone at the local club was excited and generous. And you don't have to be an expert to start—you have to be willing to be a beginner in public, and to use the tools in front of you honestly. If you've ever eyed a project well over your head and wondered whether you could get in on it: maybe. Here's a forty-year-old machine, a welcoming community a short drive away, and one hobbyist finding out.
Frequently asked
What is the Panasonic FS-A1?
The Panasonic FS-A1 is a 1986 MSX2 home computer—a compact black machine sold mostly in Japan that loaded software from cartridges and cassette tapes and starts up with a built-in software suite.
What is FujiNet?
FujiNet is a small WiFi device that gives a vintage computer a path onto the modern internet, handling the networking the old machine has no concept of and returning results in a form 1980s hardware understands. It began on the Atari 8-bit as an open-source project started by Thom Cherryhomes and has since spread to other vintage systems, including the MSX.
What's on the MSX FujiNet board?
The hardware is a prototype by FozzTexx called FujiVersal—a universal board with a machine-specific adapter (the MSX adapter here). It carries two chips: an ESP32-S3 for WiFi and a Raspberry Pi Pico (an RP2350) that runs the FujiVersal firmware and impersonates a ROM cartridge on the MSX bus.
Further reading
- FujiNet project home—what FujiNet is, which machines it supports, and the community behind it.
- FujiNetWIFI on GitHub—the open-source firmware, apps, and tools.
- FujiVersal on GitHub—FozzTexx's universal Pico firmware that lets the board impersonate a ROM on a vintage computer's bus.
- Panasonic FS-A1—MSX Wiki—specs and history of the specific machine in this build.
0 comments