What Is Punch Card?

What could we use more of today? Punch cards. Seriously: who doesn't want to be able to carry around a piece of paper with holes punched in it? We already have a system for that. It's called the Internet. It's less fun than carrying around a piece of paper with holes punched, right? A punch card is a piece of paper that can hold data in small punched holes strategically positioned to be read by computers or machines. It is an early computer programming relic used before the many data storage advances relied upon today. Punch cards were used primarily for business purposes and could be used for everything from accounting to scientific calculations. The technology was first developed in 1890 by Herman Hollerith, who invented the machine called the Tabulating Machine Company, which is known as International Business Machines. The company developed machines that could process information faster and more efficiently than any other machine. The cards were made from cardboard and measured about 4 inches wide by 7 inches tall. There were typically 80 columns on each card, allowing 8 bits of data to be stored in each column (one bit equals a 0 or 1). The holes were punched into the cards using a mechanical device called a "punch" or "puncher". Each row on the card had ten columns: A through J in even-numbered rows; K through T in odd-numbered rows; U through X in even-numbered rows; Y through Z in odd-numbered. When the first computers were being developed, they had no memory or storage. Instead, they stored information on punch cards, small pieces of paper with holes in them that could be fed into a machine. The machine would read each hole and keep it as data. These machines were called big iron machines, often used to solve complex mathematical problems. One example of this is Alan Turing's famous Turing machine.