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          Software by the yard

    Here we have a few yards of software, neatly folded in a fanfold. This was the method of choice to distribute software for minicomputers in the 70's.
    The paper tape before you is a piece of system software from Digital Equipment Corporation. It's a printer diagnostic patch for the LA180 printer. DEC would distribute such software additions and patches to its customers on paper tape, which was lightweight and easily mailed; a very durable medium, barring fire or flood. DEC fanfold paper tape
Click photo to enlarge
    Enlarge the photos on the right for close up views. The actual software code resided in the holes; each vertical line of 8 large holes represented one character (byte). The smaller holes fit a sprocket on the tape reader, which pulled the tape when it was being fed into the computer. The photo below shows the tricks you could play with these tapes - here we have a copyright notice punched in human-readable form.

    As with any software, this medium could be, and was, copied. This was done with a Paper Tape Punch - a standard item in any computer lab (PDP computers were not something you had at home, remember). The copied tape would usually come in a roll, not a neat fanfold like DEC's; an example, from the lab I was a student in, is shown in the last photo. Copy protection had not been invented yet...

Close up of paper tape

Close up of paper tape

Click a photo to enlarge

Copyright notice on paper tape

Exhibit provenance:
    I bought this one on eBay, from a vendor specializing in DEC products. It came with a few pages of documentation, printed on paper. For a device supposed to make us paperless, the minicomputer certainly consumed lots of trees!
Paper tape roll
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