Week 3 – Jss 1 Third Term Computer Lesson Notes

WEEK 3
Device
In general, a device is a machine designed for a purpose. A computer can be considered a device.
In the context of computer technology, a device is a unit of hardware, that is capable of providing input to the essential computer, receiving output or even performing both input and output operation. Computer devices can be referred to as hardware components such as: keyboards, mouse, display monitors, hard disk drives, CD-ROM players, printers, audio speakers and microphones, and other hardware units.
Peripherals are sometimes used as synonyms for devices or any input/output unit.
Class of devices

1. Mechanical devices :
   

   A machine is a tool containing one or more parts that uses energy to perform an intended action. Machines are usually powered by mechanical means. An example of mechanical device is a Generating set.

2. Electrical device :
   

   A device that produces electricity or powered by electricity. Electrical circuit devices have no decision making capability: Example is an electric Iron

3. Electronic Device :
   

   This is a device that accomplishes its purpose electronically with the capability of making decisions. These include lightweight consumer electronic device that looks like a hand-held computer which has operational capabilities.

Top of Form
Bottom of Form
Early counting Device

 
 Abacus The earliest counting device. It was invented so many years ago.
Napier’s bonesInvented by John Napier In 1614
Slide RuleIn 1620, William Oughtred developed a device called slide rule.
Leibniz’s Calculating MachineGottfried Leibniz,In 1671 he developed a machine which is also called Stepped Reckoner.
Analytical EngineCharles Babbage developed a machine called Analytical Engine in 1833. He is the Father of Computer Science.Punched CardDr. Herman Hollerith developed punched cards to solve the problem in American census in the year 1886-1887

 EXERCISE
1. Define Device
2. State the classes of devices