Card Image

Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. A card image is an archaic term for an ASCII string, usually 80 bytes in length. "Card image" refers to a punched card. IBM cards were 80 characters in length, UNIVAC cards were 90 characters. A single card typically held a single line of text, for example a line of FORTRAN code. Many data formats, such as the FITS image file format, still use card images as basic building blocks -- even though punched cards are now mostly obsolete.