ROM Rescue Switcher

The ROM Rescue Switcher is a bare-metal rescue ROM for the SidecarTridge ROM Emulator family. It boots directly from the rescue image and lets you choose another ROM image already stored on ROMEMUL, without depending on TOS, GEMDOS, BIOS, XBIOS, Kickstart, or AmigaOS.

Project links:

Table of contents
  1. What it is
  2. Supported platforms
  3. Available images
  4. Download
  5. Installing the rescue image
  6. What happens at boot
  7. Menu markers
  8. Notes for SidecarTridge products
  9. Development status

What it is

The ROM Rescue Switcher is intended as a recovery tool for ROM-emulator integrations that support a rescue image.

When the target system enters rescue mode, the switcher boots and presents a ROM chooser menu. From there, you can select another ROM image already available on the device and continue booting with that image instead of editing files from a host computer.

Supported platforms

Current builds are published for:

  • Atari ST / Mega ST
  • Atari STE / Mega STE
  • Amiga 500 / Amiga 2000

Available images

Download the image that matches your target machine and ROM size:

Target systemROM sizeRescue image file
Atari ST / Mega ST192 KBRESCUE_SWITCHER_vX.Y.Z_192KB.img
Atari STE / Mega STE256 KBRESCUE_SWITCHER_vX.Y.Z_256KB.img
Amiga 500 / Amiga 2000512 KBRESCUE_SWITCHER_vX.Y.Z_512KB.img

Replace vX.Y.Z with the actual release version you downloaded.

Download

  1. Open the project releases page.
  2. Open the latest release, or the specific release version you want to use.
  3. In the release assets, find the rescue image that matches your machine and ROM size from the table above.
  4. Download that .img file to your computer.

You can keep the original file name or rename it, but RESCUE.TXT must contain the exact final image file name.

Installing the rescue image

  1. Connect the device to your computer so the ROMEMUL volume appears.
  2. Copy the rescue image file to the root of ROMEMUL.
  3. Edit RESCUE.TXT so it contains exactly the rescue image file name.
  4. Eject the ROMEMUL volume safely.
  5. Enter rescue mode on the target system or product integration.

Always eject or unmount ROMEMUL after copying files or changing RESCUE.TXT, so the device reindexes the file list correctly.

What happens at boot

At rescue boot, the switcher:

  • starts directly from ROM without host operating system services
  • verifies its own ROM contents before entering the chooser
  • scans the images already stored on the device
  • shows a text-based selection menu
  • boots the ROM image you select

Chooser screen:

ROM Rescue Switcher chooser screen

Load confirmation screen:

ROM Rescue Switcher load confirmation screen

As in the full SWITCHER applications for TOS and Kickstart, the rescue-switcher list uses status letters to identify special ROM images:

  • A means the active or default ROM. This is the ROM image that boots when you power on the device normally.
  • R means the rescue ROM. This is the ROM image that boots when you power on the device in rescue mode.

Notes for SidecarTridge products

If you are using a product built on the ROM Emulator family, the rescue-mode procedure is product-specific:

On SidecarTridge TOS and Kickstart Emulator products, rescue mode is activated by short-circuiting the RESCUE jumper on the reverse side of the board. For user convenience, a rescue mode cable and button are included with the emulator.

TOS rescue setup:

SidecarTridge TOS rescue mode board

Kickstart rescue setup:

SidecarTridge Kickstart rescue mode board

Development status

The current project publishes active rescue-switcher builds for Atari ST, Atari STE, and Amiga Kickstart-replacement ROM setups.

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