Socket 1, originally called the "OverDrive" socket, was the second of a series of standard CPU sockets created by Intel into which various x86 microprocessors were inserted. It was an upgrade to Intel's first standard 169-pin pin grid array (PGA) socket and the first with an official designation. Socket 1 was intended as a 486 upgrade socket, and added one extra pin to prevent upgrade chips from being inserted incorrectly.