Those ancient Scroll Lock, Pause/Break, and SysRq keys still sitting on your keyboard? They're fossils from the 1985 IBM Model M 101-key layout. Zero functional use in modern systems, yet they persist purely because keyboard manufacturers never bothered to kill off the legacy design. Classic hardware inertia—once a standard gets baked in, it's almost impossible to remove even when completely obsolete. The Model M defined keyboard layouts for decades, and we're still living with its ghost keys nearly 40 years later.