Smith would pick up with a 7-4-4 code signal.

Each time he sent a new code signal he waited a moment and watched for the effect.

They kept their eyes grimly alert for a code signal.

The moment he deviated too far to left or right, the code signal ceased.

And the single word "blood" was probably a code signal that the computer recognized as an emergency.

I began to tap code signals along the tube, a request for writing materials.

You know the code signal of the robot Brain.

She must have given the code signal somewhere along the way.

It had a list, in the front, of the cartel members and what looked like a drum code signal for each.

You must have a code signal for your logic, darling.