Bell System - Preventing Data Transmission Errors - 1967 - silent

Complete Record: This is some more silent negative from my defunct film lab source. This is a Bell System film from 1967 (according to the film lab paperwork) - good views of computers, lots of oscilloscope footage, engineers, acoustic modems, paper tape. This film is a lab defect (and that's probably the only reason that I have it) - the paperwork states that the negative was 'no good' due to an object in the aperture. From a 16mm negative