Breakaway tab and plug for single reel cartridges

摘要

An erasure preventing device is located in the front wall of a cartridge which has an opening which is interactable with a cartridge drive system. A tab is irreplaceably removable from the front wall. When the tab is in place it blocks the opening and permits erasure, and when the tab is removed the opening is unblocked and prevents erasure. A removable, replaceable plug is insertable into the opening. When the plug is inserted in the opening it blocks the opening to permit erasure regardless of the presence of the tab. When the plug is removed from the opening it unblocks the opening.