Before starting

Atari publishes an official procedure for reinstalling Atari OS on Atari VCS using an Atari image written to a USB drive. Creating the installation media erases the selected drive: do not use one containing data you need to keep.

You need a computer with approximately 3.5 GB of free space and a USB 3.1 drive of at least 2 GB. Atari’s documentation does not provide a general guarantee for every USB drive here; these are the requirements stated by the official procedure.

1. Use the specified Atari image

Open the official Installing Atari OS page and use the image supplied by Atari. This article does not redistribute system images, ROMs, BIOS files or other protected files.

2. Prepare the USB drive on Windows

Atari specifies Rufus on Windows. In Rufus, select the Atari image and the intended USB drive, then use the documented settings:

• Partition scheme: MBR.
• Target system: BIOS or UEFI-CSM.

Check the selected device before starting the write: the USB drive’s contents are erased when creating the media.

3. Prepare the USB drive on macOS

On Mac, Atari specifies balenaEtcher to write the Atari image to the USB drive. Select the image, choose the intended drive, then start writing.

4. Reflash the VCS with a working display

When the VCS still displays a picture, Atari documents accessing the UEFI menu with a keyboard:

1. Turn off the Atari VCS.
2. Connect the keyboard and prepared USB drive.
3. Turn on the VCS while holding Esc.
4. Wait for the UEFI menu to open.
5. Select the USB drive.
6. Choose reflash VCS.

These labels and this sequence are those described by Atari. The page does not document every possible keyboard or UEFI firmware variant.

5. Reflash the VCS without a video signal

If no video signal is available, Atari describes another sequence: connect the prepared USB drive while the VCS is off, then turn on the console. The update may then start automatically from the drive.

Atari states approximately 15 minutes for this scenario. If the process appears not to progress, the documentation recommends a power cycle after 20 minutes. A series of updates may follow; this timing and sequence are not a guarantee of success.

USB reinstallation or factory reset?

Reflashing from a USB image differs from a factory reset. Atari places the latter under SYSTEM > GENERAL SETTINGS > FACTORY RESET and provides two choices: remove profiles and settings while keeping downloaded content, or remove downloaded games and apps.

The supplied documentation does not guarantee preservation of profiles, settings, games or apps when reinstalling from a USB image. Do not therefore assume that reflashing preserves them.

What the procedure helps you decide

• If you need to recreate the media, use only the image specified in Atari’s official procedure.
• On Windows, use Rufus with MBR and BIOS or UEFI-CSM, as specified by Atari.
• On macOS, use balenaEtcher to write the image to the USB drive.
• With a working display, open the UEFI menu and select reflash VCS.
• Without a video signal, use Atari’s documented automatic USB startup sequence.
• Do not confuse USB reflashing with FACTORY RESET, which is a separate operation.