Punched Tape - Advantages

Advantages

Punched tape does have some useful properties:

• Longevity. Although many magnetic tapes have deteriorated over time to the point that the data on them has been irretrievably lost, punched tape can be read many decades later, if acid-free paper or Mylar film is used. Some paper can degrade rapidly.
• Human accessibility. The hole patterns can be decoded visually if necessary, and torn tape can be repaired (using special all-hole pattern tape splices). Editing text on a punched tape was achieved by literally cutting and pasting the tape with scissors, glue, or by taping over a section to cover all holes and making new holes using a manual hole punch.
• Magnetic field immunity. In a machine shop full of powerful electric motors, the numerical control programs need to survive the magnetic fields generated by those motors.
• Ease of destruction. In the case of cryptographic keys, the inherent flammability (sometimes enhanced by using highly flammable material such as nitrocellulose) of paper tape was an asset. Once the key was loaded into the device, or if it may fall into enemy hands, the paper tape was simply burned.