I’m helping a friend recover access to a Bitcoin wallet that was originally set up around 2018 using someone else’s first-generation Coldcard (presumably Mk1).
My friend is not technically knowledgeable and doesn’t remember the exact setup or backup procedure.
What we currently have:
- A USB flash drive that he believes was used to store or back up the wallet.
- A handwritten sequence of 12 words.
- A handwritten 6-digit PIN.
- A Bitcoin receiving address previously used to check the balance around 2020.
We are not certain whether the original Coldcard device is still available.
What I’m trying to understand:
From the Coldcard documentation I’ve found, encrypted wallet backups can be protected by a separate 12-word password, which is different from the wallet’s BIP39 seed phrase.
I’m therefore unsure whether the handwritten 12 words represent:
- The actual BIP39 recovery phrase for the wallet; or
- A password used to decrypt a Coldcard backup file.
I’m also unsure what role the USB drive played in the original setup, since Coldcard backups are generally associated with microSD cards.
My specific questions are:
- What backup formats and methods were supported by the original Coldcard Mk1 around 2018? Were encrypted .7z backups supported at that time?
- What filenames, file extensions or other identifying characteristics should I look for to determine whether the USB drive contains a Coldcard backup?
- Assuming the USB drive contains an encrypted backup and the 12 words are its password, can the wallet be restored using a current-generation Coldcard without access to the original device?
- Would the original 6-digit PIN be relevant to restoring such a backup, or would it only be needed to unlock the original Coldcard?
I’m particularly interested in any differences between early Mk1 firmware and current Coldcard backup procedures.
My goal is to identify the original backup format and determine a safe, documented restoration procedure before attempting to access the wallet.
I haven’t entered the 12 words into any software or website, and no private recovery information has been shared.
I can provide a list of filenames and file extensions from the USB drive if that would help, but will not share the backup files or recovery credentials.
Any references to historical Coldcard Mk1 documentation or firmware behaviour would be greatly appreciated.
Used ChatGPT to make this more readable. Thank you.
