Ken Shirriff has written an excellent in-depth look at a Titan missile guidance computer:
I’ve been studying the guidance computer from a Titan II nuclear missile. This compact computer was used in the 1970s to guide a Titan II nuclear missile towards its target or send a Titan IIIC rocket into the proper orbit. The computer worked in conjunction with an Inertial Measurement Unit (IMU), a system of gyroscopes and accelerometers that tracked the rocket’s position and velocity.
See the full post at righto.com.