chadless tape

The teletypewriter machines used punched paper tape, before the invention of chadless tape.

Another disadvantage, as seen over time, was that there was no reliable way to read chadless tape by optical means employed by later high-speed readers.

A disadvantage to this mechanism was that chadless tape, once punched, did not roll up well, because the protruding flaps of paper would catch on the next layer of tape, so it could not be rolled up tightly.

However, the mechanical tape readers used in most standard-speed equipment had no problem with chadless tape, because it sensed the holes by means of blunt spring-loaded sensing pins, which easily pushed the paper flaps out of the way.