Historical Computer Engineering - Punchcard
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Punchcard

Punched Tape devices:

Tape Reader

Different to punch cards there are only three machines of major importance for punched tapes: the tape reader, the tape puncher and the repair device. The tape puncher and reader work like those for punch cards, except for the sprocket holes that had to be punched in adiitionally for feed. On optical readers the sprocket holes are used for data synchronistation. Those devices usually can read up to 1000 signs per second and there was one reader distributed by a Danish manufacturer could even read up to 2000 signs per second. The early mechanical devices used for telegraphs were only able to read about 6.66 signs per second. Later models could handle around 150 sings in the same time.

Repair Device:

This Device helps to manually repair ripped or incorrectly punched punch tapes. Therefore one can cut out the defect part with a blade and either just patch it back together without the cut off part using adhesive strip or replace it with another peace of tape. This peace may already have punched holes in it, or they can be added manually using a hole template and a stamp. It is also possible to manipulate incorrectly punched tape. While this can be really time intensive work to cut off every spoilage it is common practice to just void this section by punching the hole column.

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