HISTORY OF BARCODES
A barcode is a method of identification and data collection. Barcodes were developed in the late 1940's and early 1950's by Bernard Silver and Norman Joseph Woodland, but were not used until the mid 1970's. Barcodes used to be circular, then slowly developed into squares and rectangles. The first U.P.C(Universal Product Code) scanner was invented in June of 1973, but wasn't issued until 1974.The UPC seen on products today have 12 digits and are used to identify a product. When scanned by a laser scanner, stores are able to identify what is being bought quickly and effectively.
The first six digits on a UPC identify the manufacturer. The next five digits are used to identify the product. The last number in the sequence is called a check digit. It is calculated by the computer which reads the other numbers. Iif the computer can calculate the same digit as what was read last, it knows that it read the UPC correctly. If the computer calculates a different number than it reads, then there was an error.
Barcodes, like many other things, use the binary number system.