Old computer punch card without holes.

Caption: This is a punch card such as was used to enter Fortran programs into the mainframe system at the University of Missouri–Rolla in the late 1970s. The beveled corner on the upper left ensured that all cards were oriented the same way.

Source

I was showing my old college calculus book to my son and found several of these in the pages – we would take stacks of them from the keypunch room to use as note cards and bookmarks. I scanned the picture and claim no rights to it. Kbh3rd

Scanned and uploaded to en: by Kbh3rd.

This object is not a creative work and therefore not subject to copyright.

Jo, el titular del copyright d'aquesta obra, l'allibero al domini públic. Això s'aplica a tot el món. En alguns països això pot no ser legalment possible, en tal cas: Jo faig concessió a tothom del dret d'usar aquesta obra per a qualsevol propòsit, sense cap condició llevat d'aquelles requerides per la llei.