låsewriteprotectswitch

låsewriteprotectswitch, commonly referred to as a write protection switch, is a hardware mechanism on some removable storage devices that prevents writing to the media. When engaged, the switch signals the device or its controller to disallow write operations, effectively placing the medium in a read-only state. The protection can be accomplished by blocking the write enable path, setting a hardware or firmware flag, or otherwise instructing the controller to reject write commands.

The switch is typically a physical toggle or slider on the device or its housing. On legacy media, such as floppy disks, and on certain memory card adapters, the switch acts as a simple, mechanical or electronic barrier to writes. In many modern cards and drives, write protection may be implemented via a small electronic control rather than a visible sliding tab, and some devices do not include any write protection switch at all.

Common media that have used or may use a write protection switch include floppy disks, some SD card adapters, and other removable media where avoiding accidental data loss is desirable. However, the presence of a write protection switch does not guarantee security or immutability; software-based protections, device firmware behavior, or user permissions can override or bypass hardware switches in many cases.

Limitations and considerations include the fact that hardware write protection can be bypassed with appropriate tools or by using a different interface, and not all devices consistently honor the protection switch across all operating conditions. As storage technologies evolved, the reliance on physical write protection diminished, with software-based read-only modes and permission systems becoming more common. See also write protection, hardware read-only, and write-enable control.