User Guide

v4.0.0

Day-to-day use of the SidecarTridge TOS emulator with firmware v4.0.0: what the LEDs say, how to choose and manage your TOS images from the Atari with the SWITCHER, and how to recover with the rescue switcher when a TOS image does not start.

Table of contents
  1. Switching on
  2. The LEDs
  3. The SWITCHER
    1. The list of TOS images
    2. Select the default TOS image
    3. Upload a TOS image
    4. Rename a TOS image
    5. Delete a TOS image
    6. The board’s settings
  4. Rescue mode
    1. With the RESCUE button
    2. Without the button: RESCUE_TIMEOUT
    3. On its own
    4. The rescue switcher
    5. Change the rescue image

Switching on

Switch the Atari on as usual. The board starts the default TOS image, and the Atari boots it as if the TOS were on its own chips. A new board starts EmuTOS 1.4.

If the board is connected to a computer by USB, it shows its ROMEMUL drive instead, and the Atari does not start: unplug the USB cable first. The board only looks for a computer on the cable when it is powered on, so plugging the cable in later, with the Atari running, does nothing.

What the board does when it is powered on

The LEDs

The board has three LEDs: red, green and orange.

What the LEDs mean

  • Red: the board has power, from the Atari or from the USB cable.
  • Green: the board is serving a TOS image to the Atari.
  • Orange: the ROMEMUL drive is open on your computer; it flickers while files are copied. With the Atari running, it flashes briefly whenever the SWITCHER talks to the board.
  • Green blinking alone: the board has nothing it can serve: no TOS image chosen, or one larger than 512 KB, and no usable rescue image either. Connect it to your computer and check DEFAULT.TXT and RESCUE.TXT.
  • Green and orange blinking together: the firmware installed is for another board. Install the rp2350a update file again (Firmware installation).

The SWITCHER

SWITCHER.TOS is the program that manages your TOS images from the Atari: it lists them, sets the default one, and uploads, renames and deletes images. You can get it:

  • from the board’s ROMEMUL drive;
  • from the downloads page;
  • on a floppy disk, if you ordered one.

Copy it to a floppy or to your Atari’s hard disk and run it from the desktop like any other program. It needs SWITCHER 4.0.0 with firmware v4.0.0: an older SWITCHER stops with a “not compatible” message.

It needs an 80-column screen: medium resolution on a colour monitor, or high resolution on a monochrome one. In low resolution it only says:

The SWITCHER in low resolution

The list of TOS images

The SWITCHER opens with the list of the TOS images on the board, in alphabetical order, 17 to a page.

The SWITCHER's list of TOS images

  • The first line shows the free space on the board, how many images there are, and the page.
  • Each row shows the image’s name and size, and a letter:
    • A marks the active image: the default one, which starts when you switch the Atari on.
    • R marks the rescue image, which starts when you hold the RESCUE button.

The keys:

KeyWhat it does
UP, DOWNMove through the list
LEFT, RIGHTPrevious and next page
RETURN or ENTERMake the selected image the default one, and restart the Atari with it
UUpload an image from the Atari’s disks
DDelete the selected image
RRename the selected image
CShow the board’s settings
ESCLeave the SWITCHER

Select the default TOS image

Move to the image you want and press RETURN. The SWITCHER asks for confirmation:

Selecting a TOS image

Press any key to confirm, or ESC to go back. The SWITCHER saves the new default image on the board and restarts the Atari with it:

The SWITCHER restarting the Atari

From then on the Atari starts that image every time you switch it on. The SWITCHER also writes its name in DEFAULT.TXT, so the choice stays when you use the ROMEMUL drive.

Upload a TOS image

You can add a TOS image to the board from the Atari’s own floppy or hard disk, without a computer or opening the case.

  1. Press U. A file browser shows the Atari’s drives.

    The upload file browser

  2. Choose the image and press RETURN. The SWITCHER copies it to the board in five steps (the name, the size, the copy, a check of every byte, and a new list), showing its progress:

    Uploading a TOS image

  3. The new image appears in the list, ready to select.

Do not switch the Atari off while an image is uploading, being deleted or renamed: the board’s storage could be left damaged, and fixing it means a full firmware file.

  • The image keeps the file’s name, which on the Atari is a short 8.3 name such as TOS206DE.IMG. Rename it afterwards to give it a readable name.
  • An image larger than the free space is refused.
  • If the check finds a difference, the SWITCHER removes the image from the board and tells you; nothing is left half-copied.

Rename a TOS image

Move to the image and press R. Type the new name and press RETURN; an empty name or ESC cancels.

Renaming a TOS image

  • Names can have up to 63 characters, letters, numbers, spaces and symbols; the prompt says 64.
  • A name already in use, or one that a drive cannot store (with characters such as ? or *, or a name like CON), is refused.
  • The default and the rescue image cannot be renamed: choose another default first, or name another image in RESCUE.TXT for the rescue one.

Delete a TOS image

Move to the image and press D. The SWITCHER asks you to confirm with an uppercase Y; any other key cancels.

Deleting a TOS image

The default image, the rescue image and the last image on the board cannot be deleted.

The board’s settings

Press C to see the settings the board is using, read from CONFIG.TXT, and the SWITCHER’s version. The page only shows them: to change them, edit CONFIG.TXT on the ROMEMUL drive (Advanced Settings).

The board's settings

Rescue mode

If a TOS image does not start, the rescue image gets you back. A new board has the rescue switcher as its rescue image: a small program in the board itself, which lists your TOS images and starts the one you choose, even when nothing else boots.

There are three ways in.

With the RESCUE button

The RESCUE cable and button come with the kit. They connect to the RESCUE pins on the back of the board.

The RESCUE connector

  1. Switch the Atari off.
  2. Press and hold the RESCUE button.
  3. Switch the Atari on.
  4. Release the button once the Atari has started.

Without the button: RESCUE_TIMEOUT

v4.0.0

If the button is not wired, or the case is closed, set RESCUE_TIMEOUT in CONFIG.TXT to a number of seconds, for example 5 (Advanced Settings). Then:

  1. Switch the Atari off.
  2. Press and hold the Atari’s RESET button.
  3. Switch the Atari on, and keep RESET held for longer than the seconds you set.
  4. Release RESET: the Atari starts the rescue switcher.

A normal start is not delayed: the board waits only while the Atari is held in reset.

On its own

If the board cannot serve the default TOS image (none has been chosen yet, or it is larger than the 512 KB the board can serve), it starts the rescue image instead.

The rescue switcher

The rescue switcher shows the list of your TOS images:

The rescue switcher's list

Move with the arrow keys and press RETURN. It asks for confirmation; press any key to start that image, or ESC to go back. The Atari restarts with it.

Press T instead to test the board. The ROM Rescue Switcher page explains every screen and the test results.

An image chosen in the rescue switcher becomes the default one until you next eject the ROMEMUL drive. The board then takes the default from DEFAULT.TXT again. To keep your choice, select the image in the SWITCHER as well, or write its name in DEFAULT.TXT.

Change the rescue image

The rescue image can only be changed in RESCUE.TXT on the ROMEMUL drive (Getting Started). The SWITCHER cannot change it, on purpose: it is your way back. Keep the rescue switcher there: it can start any of your images.

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