XUSB-LSDisk - Split one USB stick into 4 independent drives (no drivers).

Hey Product Hunt 👋,
🚀 Today I’m sharing the result of a long-standing obsession: a hand-built USB controller. It does one thing, but that one thing matters — it gracefully takes back control of a storage device (its identity, each sector’s permissions, and the data itself) from the host and returns it to the device’s owner. The most tangible outcome: an ordinary USB stick or SD card can be presented as multiple disks that look completely separate to the host. On my prototype, there are four independent disks, one visible at a time (selectable via DIP).

🤔 It began with a simple belief: we should have full control over storage devices
We’re used to plugging in a drive and letting the OS take over. That model pushes critical policy into software and leaves the owner with little say. I wanted a minimal hardware proxy between host and media that enforces clear, non-negotiable boundaries at the block layer — clean multi-boot, true read-only, and private spaces the host can’t reach.

As the demo shows, the controller already delivers:
✅ Broad compatibility — standard USB Mass Storage Class (no extra drivers) across major OSes (Windows, macOS, Linux, iOS/iPadOS, Android). Works with USB flash drive and microSD Card.

✅ Multiple independent disks — one physical device becomes four presented one at a time via DIP; non-selected regions stay sealed and undetectable to the host.

✅ Transparent protection — hardware read-only the OS respects; optional per-disk encryption; hidden spaces via DIP; and a guard that rejects non-MSC identities to deter HID/BadUSB tricks.

✅ Built and tested — current prototype runs on a 120 MHz microcontroller at USB 2.0 High-Speed, with LEDs showing live read/write activity.

🚀 Detailed introduction: https://xusb.net/project-1/logical-split-disk-embodiment/
🎬 Short demo:

🤝 Looking for productization partners
Let’s talk.