Power-on password functions for computer system.

摘要

A power-on password security function executed by a CPU (10) of a digital computer system allows the system to distinguish between authorized and unauthorized users. Safeguards are made against corruption of password data which could lead to lock-out authorized users, and redundant checks allow the security function to operate even when first-level checks fail. The battery-powered RAM storage area (15) used to hold the password when the system is turned "off" is protected against being accessible by unauthorised users when the system is turned "on".