ABSTRACT
The first proposed automatic computer was the difference engine of Charles Babbage. Although Babbage conceived of using punched cards to control the sequencing of operations in 1835, their use in data processing had to wait until the 1980 census. Most large computing systems used punched cards for shelf storage and for input and output until the 1980s. Magnetic tapes are used for archival storage and companies have been offering high-performance cassette systems. Optical disks have a higher capacity and are lower in cost than magnetic disks. Unlike magnetic tape, optical disks can be accessed randomly. They are removable from the drive like floppy disks. Before 1950, electronic computers used dual-control grid tubes or multiple cathode followers for logic functions. An operating system is a program that controls the allotment of resources to the users. The first microcomputer operating system was CP/M, but MS-DOS has become the most popular system.
