Unlike desktop drives (e.g., ASUS BW-16D1HT) that require specific "friendly" firmware versions (like 3.02 or 3.10), the BU40N on 1.00 works seamlessly with any UHD disc up to BD-100 (triple layer).
LibreDrive is a feature integrated into MakeMKV. When a drive has "LibreDrive enabled," the software takes direct control of the drive’s firmware, bypassing the host's operating system limitations. With firmware 1.00, the BU40N achieves "LibreDrive Friendly" status, allowing it to read the raw encrypted data from any 4K disc regardless of region or AACS version. bu40n 1.00 firmware
| Scenario | Action | |----------|--------| | Works with your UHD rips now | – but test read speed. Old 1.00 may top out at 2x-4x read for UHD. | | You have slow UHD rips | Cross-flash to 1.00-MK (Modified, same version number but patched speed limits). | | Drive is on 1.03 or 1.04 | Downgrade to 1.00 or 1.02-MK – this is the target version for downgrading. | Unlike desktop drives (e
The BU40N is a 9.5mm slimline drive. While it is an internal laptop drive, it is most commonly used by enthusiasts in . If you are flashing your drive to 1.00, ensure your USB enclosure uses a high-quality bridge chip (like those from Vantec or OWC), as cheap adapters can cause the flash process to fail. With firmware 1
: This specific version enables permanent microcode access, bypassing restrictive AACS protections and "revocation" lists. Ease of Use & Installation Complex Process
The (specifically the "Downgrade Enabled" or "DE" version) is considered the "gold standard" for enthusiasts who rip 4K Ultra HD (UHD) Blu-rays. While newer official firmwares (1.01–1.05) often block unauthorized reading of UHD discs to satisfy DRM requirements, the 1.00 DE firmware removes these restrictions, turning the BU40N into a "UHD-friendly" drive. Why Firmware 1.00 is Recommended