http://alvroble.com/tags/open-source/Recent content in Open-Source on alvrobleHugoen-USMon, 05 Oct 2026 00:00:00 +0000http://alvroble.com/posts/2026-10-05-savepoint-signer/Mon, 05 Oct 2026 00:00:00 +0000http://alvroble.com/posts/2026-10-05-savepoint-signer/<p>There is a Bitcoin signer hidden in New Bark Town.</p> <p>You are playing Pokémon Crystal. You stop at an ordinary town sign, read it, and interact again. A hidden menu opens: recover a test seed, verify your account, review a transaction, and approve its signature. Lock the session, and you are back in the adventure.</p> <p><a href="https://github.com/alvroble/savepoint-signer" target="_blank" rel="noopener">Savepoint Signer</a> turns a familiar handheld into an experimental offline Bitcoin signer. No Wi-Fi, no Bluetooth, no cloud account. Just the screen and buttons you already know, a modified game cartridge, and a microSD card that carries transaction files between the handheld and your computer. Its signing interface lives inside the game's world, waiting to be discovered.</p>