Retro computing on Raspberry Pi Pico and RP2040 and RP2350 steroids. Revitalize your vintage computers with our devices, a series of coprocessor boards.
Logroño/Madrid/Atariland
Joined August 2023
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🚀 1/n This weekend, I unveiled Version 3 of the @SidecarTridge Multi-Device board! Time to dive into what’s new—how I made it better, slimmer, more compact, and even cheaper. Let’s break it down. 🧵👇
We have a new place to shout from: SidecarTridge News, our Telegram channel.
Firmware releases, new disks in the Atari ST Public Floppy Database, restocks and the occasional board that refuses to behave. If it lands on X, it lands there too, so you can follow along without an X account and without an algorithm deciding what you see.
It is a broadcast channel, so no notifications from 400 strangers arguing about TOS versions. Just us, posting when there is something worth posting.
Join here:
t.me/sidecartridgenews
No Telegram? You can read it in any browser:
t.me/s/sidecartridgenews
And yes, we are also back on Mastodon: oldbytes.space/@sidecartridg…
In 1989 a decent arcade conversion for the ST took a team, a year, a pile of graph paper and somebody's sanity. In 2026 it takes a weekend, a good bunch of Claude tokens and a chat window. And the result is much better. We are not crying, you are crying.
Anyway, nine new disks just landed in the Atari ST Public Floppy Database, and most of them were ported with AI coding tools:
ZAXXON 1.2, the isometric shooter, for the STE.
CRILLION, the 1988 C64 game where the ball bounces by itself and you only get to steer.
YARS REVENGE, the 2600 classic, insect warrior against the Qotile.
Mario Bros 1.1, the Nintendo arcade original.
COMBAT Remastered, the 2600 tank duel with a new coat of paint.
DIGDUG 1.1, the arcade digger.
Stop the Express, the Hudson Soft Spectrum game, ported by cbragatto with the original graphics and sounds.
Bruce Lee, one and two player versions, ported by TjLaZer from Kagesan's Master System version. Full palette and DMA sound on an STE, still happy on a plain ST.
The coders of 1989 would need a drink. We'll just play them.
One disk each. Real hardware with a SidecarTridge Multidevice or a Gotek style drive, or your favourite emulator.
ataristpublicfloppydb.sideca…
Firmware v4.0.0 for the SidecarTridge TOS Emulator and Kickstart Multi ROM is out. The biggest update these boards have had, and it brings a new SWITCHER and a new rescue switcher with it, because the three now speak a new protocol and flatly refuse to talk to their older siblings. Family drama, ROM edition.
What's new:
No RESCUE button at hand, or the case already closed? Set RESCUE_TIMEOUT in CONFIG.TXT, power on holding RESET, and the board drops into rescue mode by itself.
Accelerator board fitted? ACCELERATED_BUS runs every boot at full clock, about 25% faster, so some accelerator boards that used to struggle may now work. Not magic, but worth a try.
Your computer always gets something to boot: if the default ROM can't be used, the board starts the rescue ROM instead of a black screen.
The ROMEMUL drive is tougher, with a pile of fixes, and the firmware refuses to run on a board it wasn't built for.
The SWITCHER has a configuration page (press C) that shows what the board is running with.
The rescue switcher has a self-test. Press T and it checks every address and data line, hammers the board with thousands of random reads, then names your machine, monitor and RAM. Press S for a 30 second soak: 265,905 reads and zero errors in the screenshot. Next time someone says "it's the cartridge", you'll have numbers.
What's fixed:
Mac users with around 29 ROMs or more: the hidden ._ files macOS sprinkles everywhere could wreck the ROM list. Thanks, Apple. Fixed on both sides.
The SWITCHER leaked memory every time you went back to the list, and a 512 KB machine eventually crashed. Plugged.
Monochrome STs could boot the rescue screen shifted sideways. Straightened.
Upgrading from firmware v3.x keeps your ROMs, but you have to replace the SWITCHER and the rescue switcher too, or they'll sulk at an incompatibility screen:
docs.sidecartridge.com/sidec…
docs.sidecartridge.com/sidec…
For board revision 3. Board revisions 1 and 2 stay on firmware v2.1.0.
Flash it from your browser:
webflash.sidecartridge.com
I need this to slam factory firmware into my devices one after another, a firmware assembly line on steroids
The SidecarT as a GPU
ROTT Accelerator for @SidecarTridge Multi-device now enables you to play Rise of the Triad at up to 30fps with music and sound enabled: Bigger, better and more ludicrous than ever before, even on an 8MHz #AtariST!
Available now in the Multi-device app store.
#ROTT #RetroGaming #Homebrew
In 1990 Andreas Kromke (the author of KAOS TOS, the heavily modified and performance-tuned TOS for the ST range) looked at TOS and said: one program at a time? No, thanks. Mag!X was born, later MagiC: a real multitasking OS for the Atari ST, with several GEM apps running side by side in their own windows, and still happy with software written for TOS.
It was a commercial product for years. Then Kromke did something few authors do: he opened the complete sources under the GPLv3. And this year he shipped MagiC 6.30 for Atari computers. In 2026. On a 68000. Respect.
Normally MagiC boots from disk: TOS starts first, then a loader pulls the kernel into RAM. We thought that was a waste of perfectly good RAM, so we built the MagiC ROM Builder. It turns MagiC 6.30 into a 256 KB ROM image that boots in place of TOS, plus the boot floppy or hard disk files for its desktop. Everything happens in your browser, nothing to install.
Flash it with the SidecarTridge TOS Emulator on an STE or Mega STE, or on an ST or Mega ST with the 256KB Decoder. No TOS needed, around 240 KB more free RAM, and it boots straight into a multitasking desktop.
Build your ROM:
magic.sidecartridge.com/
MagiC sources by Andreas Kromke:
gitlab.com/AndreasK/Atari-Ma…
Unlike the Croissant, the Soufflè is a design I actually enjoyed. This one has real hardware meat on its bones.
First boss: the USB hub. Getting a hub to play nicely with the USB port of a Raspberry Pi Pico 2 W is harder than it sounds, because not all of them work. Learning how those tiny, hyper-specialised hub controllers actually think turned out to be a lot of fun.
Second boss: power. Every USB device you plug in wants its share, and the Atari has to feed all of them. On a Mega ST that's no big deal. On a Mega STE or a TT it is, because those machines have a fuse to stop exactly this kind of party. So the USB ports are current-limited to keep your computer from being drained.
Third boss: two power sources. All my circuits protect against dual voltage input, and here I picked a simple rule. Powered from the Atari, the USB hub is on. Powered from the Pico 2 W's micro USB, the hub is off and the port stays free for things like firmware updates.
All this juggling comes with one rule on the Mega STE: Bluetooth and the USB hub at the same time are forbidden, because together they exceed the theoretical limit the machine can supply and its fuse would blow. Theoretical, because I never managed to blow it. I might add a "Suicidal mode" for anyone brave enough to try it on their own Mega STE. Mega ST owners, you're welcome to it too.
As usual, the source code:
The emulator itself, with the original HD6301 code:
github.com/sidecartridge/rp2…
The loader, a variant of the Multi-device's Booster:
github.com/sidecartridge/rp2…
And the video, for anyone who still doesn't know what it is:
youtube.com/watch?v=k-8jHeQD…
SidecarTridge retweeted
I just fed the Atari ST Turbo Cup disk image into Claude. I love this game, but the slow framerate annoys me.
Claude adapted the game to use STE DMA sound and blitter, and optimised a load of 68k code, resulting in an overall 45%(ish) speed increase.
Mind officially blown. 🤯
SidecarTridge retweeted
Intentando hacer una versión fullscreen de Zynaps de Atari ST empujada por el @sidecartridge Un 33% mas de área de juego.
SidecarTridge retweeted
Nope. There are plenty of projects using fieldofcows project to build their own devices with USB support. Yet none of them offer full Bluetooth support. Why?
1. Limited Bluetooth support: The only implementation that actually worked on the RP2040 and RP2350 was Bluepad32, which primarily focused on gamepads. My PRs addressed that limitation by adding proper keyboard and mouse support, particularly for low-cost devices that don't fully implement the Bluetooth stack.
2. A real bug in the Pico SDK: There was an actual bug in the Pico SDK's handling of TLV storage in BlueKitchen's BTstack. I identified and reported the issue, and my code includes a workaround. The underlying bug has since been fixed (hopefully!).
I've never had a problem giving 'fieldofcows' credit. His work has been a cornerstone of my projects and products, and I've always been pretty damn clear about that.
But let's give credit too where it's due: the guy who originally wrote the HD6301 emulation for STeem back in the day did some of the real heavy lifting. That's the kind of work that deserves serious respect. Thank you, Arne Riiber.
And while we're handing out kudos, let's talk about Ricardo Quesada, the mastermind behind Bluepad32. That guy is a legend. BTstack is one hell of a beast to tame. Trust me, I know firsthand how tough is BlueKitchen GmbH's work. So I know exactly how nasty that rabbit hole can get. Ricardo tackled it brilliantly, and he deserves a massive hat tip for it.
Here's the thing: building products is about standing on the shoulders of other people's work, adding your own blood, sweat, and nowadays adding some IA token burning along the way.
Nobody builds this stuff out of thin air. But when you put something out in public, giving proper credit isn't just good manners. It's basic f*cking decency.
I almost didn't release the Croissant.
As a hardware design it's not exactly rocket science. The schematics are in the docs, so anyone can build their own. The interesting part is the software, and that stands on the shoulders of a brilliant idea by fieldofcows: emulating the Hitachi 6301, the chip that handles keyboard, mouse and joystick on the Atari ST/STE, inside a Raspberry Pi Pico. That code was the seed for both Croissant and Soufflè, which share the same codebase.
So what pushed me to finish it? Someone kept dropping into the old SidecarTridge Discord asking how to build his own Croissant. Fine by me, helping people build stuff is half the fun. A few weeks later he posted his version on Atari Forum: Claude Code 2025 vibe-coded, with a PCB featuring some truly "creative" choices, thanking every body one by one for their help. Everyone except me.
The best part: to get Bluetooth working smoothly with every device, the Bluepad32 library needed some surgery. I did that surgery. He was running my version of the library and he had no idea.
In a scene where nobody makes money and recognition is the only currency, that one stung. Add the growing dose of insults on Discord and the decision was easy: goodbye, Discord. Hello, finished Croissant.
Confession: I never enjoyed designing this one, and it turned out to be one of our best sellers. Life. My favourite is the Soufflè, that one was a real challenge.
Bonus tip most people don't know: Croissant also works with USB devices. Flash the Soufflè firmware and plug a USB hub into the Pico W's micro USB port.
Here's the video for anyone who still doesn't know what it is:
youtube.com/watch?v=mTe4EGKS…
The repos.
The emulator in itself with the original HD6301 code:
github.com/sidecartridge/rp2…
The loader. It is a variant of the Multidevice's Booster:
github.com/sidecartridge/rp2…
The link to the gerbers:
docs.sidecartridge.com/sidec…
And the link to the original repo from 'fieldofcows':
github.com/fieldofcows/atari…
What a weekend!!!!
Last year, I ported Rise of the Triad to #AtariST.
This year, I made it playable!
ROTT Accelerator enables your ST to render in-game action at 15fps: beta release now available in the @SidecarTridge Multi-device app store.
#ROTT #RetroGaming #Homebrew
Dragon's Lair is here for the SidecarTridge Multi-device.
In 1983 it needed a laserdisc player the size of a fridge and ate your quarters faster than Singe eats knights. In 2026 it fits in your Atari ST's cartridge slot. Yes, really.
The whole Don Bluth cartoon, full screen at 25 pictures a second, with sound, on a plain ST, STE, Mega ST or Mega STE. No laserdisc. No coin slot. No mercy. Just you, a joystick and a dragon who has been waiting 43 years for a rematch.
Personal note: at 15 I was the undisputed king of that cabinet. I had every single move burned into my brain and could finish (well... sort of) the game with my eyes half closed. Now I'm closer to 60 than to 50, and some mornings I can't remember where I left my glasses. So I built oldies mode: the game shows you the next move before Dirk turns into a pile of bones. Proudly made for those of us whose RAM is starting to leak.
Watch Dirk die so you don't have to:
youtube.com/watch?v=-Uulwd8h…
How to set it up:
docs.sidecartridge.com/sidec…
Grab your sword. Daphne is not going to rescue herself. Well, she could. But it's 1983.
The coolest computer recreation so far!
atari.com/pages/800xl
Your Atari ST and your PC have been forced to share floppies for 40 years. Time to end that toxic relationship.
The File & Download Manager for the SidecarTridge Multi-device just got a serious upgrade, and now your phone does the dirty work.
Search the public floppy database from the sofa, tap download, and the image lands on the microSD card. No PC. No USB stick. No crawling under the desk to find the floppy drive cable.
And it no longer stops at downloading:
Unzip a release right on the card. Convert MSA to ST and back. Turn Pasti STX images into plain ST (it even tells you beforehand if you'll lose anything). Create blank disks in any size. Open an ST image like a folder and drop files in or pull them out. Paste a link and it downloads the file straight to the card.
All from a browser, while the Atari sits there looking smug.
Watch it in action:
youtu.be/ijC1k_QQUK0
Docs:
docs.sidecartridge.com/sidec…
Your floppy drive called. It wants to retire.
SidecarTridge retweeted
If your Cubase dongle for AtariST is dead, with SidecarTridge you can emulate it youtu.be/GVr4cxAfPFU #atari
One of the most frustrating things we keep seeing is people buying the SidecarTridge Multidevice Kit and then soldering in some random, crappy Pico W from a shady seller to save a few bucks.
And then, surprise: things don’t work properly.
So we’re done with that. We’ll stop selling the kit on its own and will only sell it with Pico W boards sourced from suppliers we actually trust.
Less mystery hardware, fewer stupid problems.
ROM Emulator v2.2.0 is here for the SidecarTridge Multi-device.
This one is less about new tricks and more about showing what Firmware V2 can do: a fresh setup screen, an online catalog of cartridge ROMs and downloads straight from your Atari (ST, STE, Mega ST, Mega STE, TT, Falcon). The walkthrough video takes you through all of it.
Walkthrough video:
youtu.be/ZXChTIENiyo
Quick confession: we keep meeting Multi-devices still running firmware v1.x. That version reached the end of its support a while ago, and everything new, this app included, lives in V2. Updating is free and takes a couple of minutes from your browser:
docs.sidecartridge.com/sidec…
ROM Emulator docs:
docs.sidecartridge.com/sidec…
