This document provides an overview of different computer input/output and storage devices. It describes line printers, impact and non-impact printers, card readers, paper tape readers, magnetic ink readers, and optical character readers as common input/output units. Magnetic tape units, magnetic disk units, and magnetic drum units are discussed as storage devices, with magnetic tape being popular for batch processing and magnetic disks allowing random access.

1. Computer Systems HardwareLesson 10

2. 10 – 1 Input /Output Units10 -2 Types of Input / Output UnitsLine PointerCard Read / Punch MachinePaper Tape ReaderMagnetic Ink ReaderOptical Character Reader10-3 Storage Devices

3. Input / Output UnitsThese devices are used to provide link between the machine and its users.These devices may include :PrintersCard readersPaper tape readersMagnetic ink readersOptical character readers

4. Types of Input / Output UnitsLine Printer – an output device that produces data in readable form.Impact printer – prints by means of type striking an inked ribbon and paper.Non-impact printer – prints by chemical or photographic means.Card Read / Punch MachineIn earlier computers, punched cards were used primarily for inputting source data.The device that inputs data on punched cards is called a card reader and the output device is called a card punch

5. Types of Input / Output Units Paper Tape ReaderIt provides direct input to a computer by reading data prepunched on paper tape.

6. It provides output froma computer by punching output information unto the same medium.Magnetic Ink ReaderIt is a specialized input device that can read checks and other paper documents that have been imprinted with magnetic ink in a special font.Types of Input / Output Units Optical Character ReaderIt is commonly referred to as an optical scanner, reads marks, bars , letters, numbers and certain special characters from printed documents Storage DevicesMagnetic Tape Units The most popular sequential storage mediumOne of the most common file types for storing high-volume data that is processed in a batch mode and is used for both output and input of data.Magnetic Disk UnitsThe most popular random-access storage mediumFirst Type: the disks are fixedSecond Type : the disk can be removed in the form of a disk packThird type : accommodates the small floppy disk

7. Storage DevicesMagnetic Drum UnitsAnother type of random –access secondary storage device.It was used in 3rd and 4th generation computersThey are not as versatile as magnetic disk units and are now being phased out