Write protection

A write protection is a mechanical or electronic protection device on data storage media such as floppy disks, removable disks, audio cassettes, video cassettes, Mini Disc and USB flash drives, prevents data ( unintentionally ) can be deleted or changed. Similarly, the operating system or the software can provide a file with a write protection.

With the older 5 - ¼ -inch floppy write score, which is glued to the write protection with metal foil exist. When the 8- inch floppy disks, it is vice versa: With open notch the floppy disk is write-protected.

With 3 - ½ -inch diskette is used as a write-protect slide, which closes an opening (recordable ) or releases ( protected). In many 3 - ½ -inch diskette delivered programs of the write-protect tab has been omitted to save manufacturing costs and to prevent accidental deletion of the disk. In this case, the disc can still be used after the program is no longer needed by the write-protect hole is unobstructed.

For a VHS tape and an audio cassette of the write protection is realized by breaking the tab on the rear long side. Rarely in a video cassette also a write-protect switch is employed. All pre-recorded video or audio cassettes (so-called purchase cassettes) are read-only by the manufacturer so. You find the same by simply gluing the write-protect hole of the write protection.

At a hardware level, internally realized write protection this is not possible. This is blown controlled by a higher power, the control line for the write permission for the successful storage of the data and thus enabled the write protection. This is, for example, used for storage and smart cards that contain critical data.

SD and SDHC memory cards have on the left a small plastic slide. This is read by a contact in the card reader to determine whether the card is write-protected.

• Storage medium