In the 1980s and early 1990s, IBM Personal Computers and some PC compatibles included a tubular pin tumbler lock on the computer's casing performing a security function that varied by manufacturer. In some instances, the lock would prevent the case from being opened to inhibit the theft or modification of internal components. In other cases, the lock was used to forbid unauthorized access to the computer by disabling the power supply, hard drive, or keyboard.
Built-in computer locks for access control were phased out by computer manufacturers in the 1990s as operating systems and other software incorporated user profiles with passwords, but computer locks to prevent theft are still in use, more commonly in the form of Kensington locks that attach cables to laptops and small desktops in an effort to prevent them from being taken.
- "The Turbo Button And The Key Lock On Old Computers". Francis Universe. Retrieved 2 December 2019.
- Basinger, Clint. "Why did old PCs have key locks?". YouTube. Retrieved 2 December 2019.