15 of IBM 80 Column SQUARE corners DATA Key-Punch Cards (Hollerith) MINT
VINTAGE IBM (Hollerith) punch card. Punch cards were used in the 1890 census, virtually all punch cards had square corners, until IBM patented and began using rounded corers in 1964. My cards have SQUARE corners.I originally purchased In bulk 2000 per box, in the early 1970's. The cards have never been used, or for that matter out of the original box. These are clean, unused, and show absolutely no visible signs of aging.Standard shipping does not include tracking. If you want tracking select First Class Pack or Priority Mail option at checkout.