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External Drive Reader

A USB stick or SD card can work as a Zaparoo token. Put a zaparoo.txt file on the drive, plug it into the device running Core, and Zaparoo scans the file contents.

This is useful if you want physical tokens without buying NFC cards or a separate reader.

Platforms​

Base OS
WindowsSupported
macOSSupported
LinuxSupported
FPGA
MiSTerSupported
MiSTeXSupported
Retro Gaming OS
BatoceraSupported
RePlayOSSupported
Handheld and Gaming Linux
SteamOSSupported
BazziteSupported
ChimeraOSSupported
Media Center
LibreELECSupported

Enable the reader​

The reader is disabled by default. Add this to your config.toml:

[[readers.connect]]
driver = "externaldrive"
enabled = true

Restart Core after changing the config.

A readers.connect entry makes this reader active unless you have explicitly disabled the driver elsewhere. You can also enable the driver directly:

[readers.drivers.externaldrive]
enabled = true

Make a drive token​

  1. Format a USB stick or SD card using a filesystem your device can mount.
  2. Create a plain text file named zaparoo.txt at the top level of the drive.
  3. Put the ZapScript in the file.
  4. Eject the drive, then insert it into the device running Core.

Example zaparoo.txt:

**launch.random:SNES

The filename is matched case-insensitively, so zaparoo.txt, ZAPAROO.TXT, and similar casing work.

What happens when you insert it​

When the drive mounts, Core looks for zaparoo.txt. If it finds one, it trims surrounding whitespace and scans the remaining text as an externaldrive token. On Linux, Core can also find the file on sibling partitions mounted under /media or /mnt, which helps with multi-partition USB drives.

Removing or ejecting the drive clears the active token, similar to removing an NFC card from a reader.

Core ignores the file if:

  • It is empty or only contains whitespace
  • It is inside a folder instead of at the top level of the drive
  • It is a folder named zaparoo.txt rather than a file
  • It is a symlink
  • It is larger than 1 MiB

The reader does not write anything back to the drive. You create and edit zaparoo.txt yourself.

Detected drives​

Core watches for removable drive mount events. It does not scan every mounted disk on the system, and that distinction matters for USB hard drives.

  • Windows detects drives reported by Windows as removable, such as many USB sticks and SD card readers.
  • Linux uses UDisks2 when available. Without UDisks2, Core falls back to /proc/mounts and only watches removable mounts under /media or /mnt.
  • MiSTer, Batocera, SteamOS, and similar Linux-based systems depend on the fallback behavior if UDisks2 is not available.
  • macOS detects removable volumes mounted under /Volumes.

Some USB hard drives and SSDs are reported by the operating system as fixed or internal disks. Those may not be picked up by this reader.

Troubleshooting​

Drive not detected​

Check your config first:

[[readers.connect]]
driver = "externaldrive"
enabled = true

If you use driver settings, make sure the driver has not been disabled:

[readers.drivers.externaldrive]
enabled = true

Then check the basics:

  1. Restart Core after changing config.toml.
  2. Confirm the operating system mounted the drive.
  3. On Linux-based systems, check whether the drive mounted under /media or /mnt.
  4. Enable debug_logging = true in config.toml and check the Core logs.

File ignored​

Make sure zaparoo.txt is a normal text file at the top level of the drive. The name can use any case.

The file must not be empty, whitespace-only, a symlink, or larger than 1 MiB.

ZapScript not running​

Test the same text with another reader or through the app. If it still does not work, the ZapScript probably needs fixing.

Check the ZapScript docs for syntax.