Unit-III
Mrs. Kiran Bala Dubey
Assistant Professor
Department of Computer Science
Govt. N. P. G. College of Science,
Raipur
, Contents
• Central Processing Unit
• Microprocessor
• Control Unit
• ALU
• Registers
• Buses
• Main Memory RAM
• ROM
• Storage device
• Primary & Secondary Storage
• Data Storage & Retrieval Methods- Sequential, Direct & Indexed Sequential
• Tape storage & retrieval methods
• Direct access storage & microcomputers
• Hard disk
• Disk cartridges
• DASD
• Optical disks
• CD ROM
, The central processing unit (CPU) consists of six main components:
• control unit (CU)
• arithmetic logic unit (ALU)
• registers
• Buses
• Cache
• clock
All the components work together to allow processing and system
control.
• Cache is a small amount of high-speed random access memory (RAM) built directly within the
processor. It is used to temporarily hold data and instructions that the processor is likely to reuse.
This allows for faster processing, as the processor does not have to wait for the data and
instructions to be fetched from the RAM.
• The CPU contains a clock which, along with the CU, is used to coordinate all of the computer's
components. The clock sends out a regular electrical pulse which synchronizes (keeps in time) all
the components.The frequency of the pulses is known as clock speed. Clock speed is measured
in hertz (Hz).