SidecarTridge TOS Emulator
The SidecarTridge TOS emulator is a compact board that emulates Atari ST internal ROMs, enabling users to run any TOS version or custom ROM without physically swapping chips.
This guide offers comprehensive information about the SidecarTridge TOS emulator for the Atari ST family of computers. Explore the relevant sections below to find specific details.
If you want a quick overview of Atari TOS ROM history before diving into the docs, these two videos are a good starting point:
These docs keep two numbers apart: the board revision is the hardware you have, and the firmware version is the software that runs on it.
🚀 Which board do I have?
| Your board | How to recognise it | Firmware | Start here |
|---|---|---|---|
| Board revision 3 (RP2350) | Wider, soldered castellated board. Red power LED, green LED (firmware running) and orange LED (USB drive mounted). | Firmware v4.0.0 (current), with SWITCHER 4.0.0 and the rescue switcher 4.0.0 | Getting Started, or Upgrading from firmware v3.x (keeps your TOS images) |
| Board revisions 1 and 2 (RP2040) | Slimmer board, mounted with a short pin header. No red power LED. | Firmware v2.1.0 (final for these boards), with SWITCHER 2.1.0 | Firmware v2.x: Getting started and Firmware v2.x: User Guide |
In the image above, board revisions 1 and 2 appear on the left, and board revision 3 on the right.
ALL BOARDS SHIPPED AFTER MID JUNE 2025 ARE BOARD REVISION 3.
Visit the official downloads page to get the latest firmware and applications, or install the firmware from your browser at webflash.sidecartridge.com.
Table of Contents
📘 Introduction
An overview of the SidecarTridge TOS emulator project, explaining the project's purpose, objectives, and the intended audience.
🚀 Getting started
Guidance on the initial steps including prerequisites, setup and configuration.
⬆️ Upgrading to v4.0.0
Move a board revision 3 from firmware v3.x to firmware v4.0.0, keeping your TOS images.
Guides for board revisions 1 and 2 (RP2040)
Firmware v2.x: Getting started
The current guide for board revisions 1 and 2, which stay on firmware v2.1.0.
Firmware v2.x: User Guide
The current guide for board revisions 1 and 2, which stay on firmware v2.1.0.
Archived guides
Firmware v3.x on board revision 3: Getting started
Firmware v3.x is replaced by firmware v4.0.0. See Upgrading to v4.0.0.
Firmware v3.x on board revision 3: User Guide
Firmware v3.x is replaced by firmware v4.0.0. See Upgrading to v4.0.0.