What's New in beta-v0.0.17 (Changelog)


A multi-device emulator for the Atari ST, STE, and Mega series on Raspberry Pi Pico steroids.

SidecarT is a state-of-the-art cartridge ROM emulator crafted for the Atari ST, STE, and Mega series. It leverages the robust capabilities of the RP2040 microcontroller found in the Raspberry Pi Pico, enabling it to:

  • Emulate both 64Kbyte and 128Kbyte ROMs by simply loading the binary files from a microSD card or via a Wi-Fi connection.
  • Interact with the cartridge bus in real-time for data reading and writing, which allows for seamless emulation of devices such as floppy disks, hard disks , real-time clocks, keyboards, mouse devices, and more.
  • Dive into a realm of possibilities, limited only by your creativity. Thanks to its open architecture and the open-source code, SidecarT can evolve to meet any challenge you envision.


  1. Versatile ROM Emulation: Easily emulate 64Kbyte and 128Kbyte ROMs. With SidecarT, switching between ROMs is a breeze—simply load the binary files either from a microSD card or directly via a Wifi connection.
  2. Real-time Cartridge Bus Interaction: SidecarT isn't just for ROMs. It's built to interact with the cartridge bus on-the-fly, making data reading and writing seamless. This real-time integration allows for an enriched experience, especially when emulating devices.
  3. Diverse Device Emulation: From hard disks and floppy disks to real-time clocks, keyboards, and mouse devices, SidecarT has you covered. Its advanced capabilities ensure you get an authentic emulation experience across a range of devices.
  4. Open Source & Customizable: At its core, SidecarT is designed for innovation. With open-source code and architecture, you have the freedom to tweak, modify, and expand its functionalities. It's not just an emulator—it's a canvas for all your tech endeavors.
  5. Powered by Raspberry Pi Pico: Thanks to the prowess of the RP2040 microcontroller in the Raspberry Pi Pico, SidecarT delivers exceptional performance and reliability. It's the perfect blend of old-school charm and modern-day tech.
  6. Ever-evolving Capabilities: The world of Atari ST and its series is vast, a major retro platform. SidecarT is built to evolve, ensuring that you're always at the forefront of emulation technology.

How It Works

Getting started with SidecarT is straightforward and intuitive. Here's a step-by-step guide:

  1. Setup the Hardware: Ensure that the Atari ST computer is powered off. Insert the SidecarT device into the Atari ST's lateral cartridge interface and power on the computer.
  2. Initiate SidecarT: Hold down the SELECT button on the SidecarT for more than one second and run the SIDECART.TOS application.
  3. Obtain your ROMs, Floppy images or hard disk files: Using the Atari ST interface, you can easily connect to the web. Dive in, explore, and download your favorite ROMs, Floppy images or hard disk files from the curated lists we've prepared. It's a seamless experience, connecting you directly to HTTP servers for your convenience.
  4. Choose Your Functionality: You'll have an option to select the function of the SidecarT device. You can emulate a ROM, a Floppy Drive, a Hard disk drive and a Real Time Clock out of the box.
  5. Start the Emulation: Either reset your Atari ST computer or power cycle it. SidecarT will now operate as the selected emulated ROM cartridge. This behavior persists even if you switch the computer on and off. If you wish to emulate a different ROM or use another function, simply start over from the second step.
  6. Dive In and Enjoy: With everything set up, all that's left is for you to enjoy the immersive experience SidecarT offers!

See it in action



Floppy Emulation and Atari ST database browse


Hard Disk Emulation

Buy a SidecarT



Visit our online shop online shop for more options and configurations.

Frequently Asked Questions

Is the SidecarT for me?
SidecarT it's a homebrew product designed for hobbyists with a keen interest in experimenting with their computers.
If you seek a seamless, Apple-like experience, SidecarT will not meet your expectations.
Can the device harm my computer?
SidecarT has undergone extensive testing on various Atari ST, STE, MegaST, and MegaSTE computers featuring diverse TOS versions. However, it's important to note that this version does not support Atari TT, Falcon computers, and their clones. While heavily modified and customized computers are likely compatible, it's up to you to decide to use the SidecarT. As a rule of thumb, it's guaranteed to work with any computer at 8Mhz speed.
Why don't you ship to some European countries?
I've made the difficult decision to discontinue shipping to Austria, Bulgaria, Cyprus, France, Greece, Latvia, Lithuania, Luxembourg, Portugal, Romania, Slovakia and Sweden. This decision was not made lightly and is primarily due to the specific and significant costs associated with recycling packaging and electronics in these countries. Unfortunately, these costs are disproportionately high relative to the demand I've experienced, making it unsustainable for me to offer the products in these markets and while adhering strictly to the legal requirements.
Why are you open-sourcing the code?
Adopting the General Purpose License for the source code is my way of ensuring that the benefits belong to the community at large, rather than being held by a particular individual or entity.
Why are you open-sourcing the design with restrictions?
The essence of this project lies in community involvement and sheer passion, not profit-making. It's disheartening to envision entities or individuals merely reproducing the design for commercial gains without adding any substantial value. While I'm completely supportive of enthusiasts creating their own SidecarT for personal use or for fellow aficionados, those aiming for monetary benefits should recognize the efforts and intentions behind this initiative. If profits are to be made, they should rightfully support the original creator.
Can I contribute to the project?
Of course! Please visit the Documentation site page to learn how to start contributing to the project! No matter if you are a microcontroller ninja, an Atari ST guru, or a C aficionado. You are welcome!
Where can I find ROM images?
I have gathered some images in this directory. You can download them, or simply connect the SidecarT to your Wi-Fi and browse the catalog online from your Atari ST!
Where can I find floppy images?
Just like in Soviet Russia, you don't need to find applications. The applications find you! You can use the embedded application search engine to find the application you need. Just type the name of the application and press enter. The floppy disk image with the application will be automatically downloaded and launched.
Which Option is Most Suitable for Countries within the European Union?
It does not matter. Any available options can be ordered, and the anticipated delivery time is between 3 to 5 business days.
What is the Advisable Option for European Countries Not Part of the EU?
The specific customs tax amounts are unclear; therefore, choosing a more economical option is suggested. It is recommended to choose the SidecarT Single Board - RPi Pico W with headers NOT INCLUDED and try to purchase a RPi Pico WH within your locality to save costs. Expect delivery to take approximately 3 to 5 business days.
Which Option is Optimal for Countries Outside Europe?
Similar to countries outside the EU, it is advised to choose a cost-effective option and order the SidecarT Single Board - RPi Pico W with headers NOT INCLUDED, securing a RPi Pico WH through a local dealer. Delivery to these locations is estimated to take between 5 to 15 business days, with the exact timing being quite unpredictable.


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