Even before the first computer was conceptualized, data had already been
stored on hard copy medium and used with a machine. As early as 1801, the
punched card was used as a control device for mechanical looms. One and
one-half centuries later, IBM joined punched cards to computers, encoding
binary information as patterns of small rectangular holes. Today, punch
cards are rarely used with computers. Instead, they are used for a handful
of train tickets and election ballots. Although some may find it
surprising, a computer printout is another type of hard copy medium.
Pictures, barcodes, and term papers are modern examples of data storage
that can later be retrieved using optical technology. Although it
consumes physical space and requires proper care, non-acidic paper
printouts can hold information for centuries. If long-term storage is not
of prime concern, magnetic medium can retain tremendous amounts of data
and consume less space than a single pie...