LESSON 7 Flashcards
The basic parts of the computer system are:
➢
Input Unit
➢
The Central Processing Unit
➢
Output Unit
It is the part of the computer that carries out the instructions of a computer program.
It is the unit that reads and executes program instructions. Hence it is known as the brain
of the computer. The CPU consists of a storage or memory unit, Arithmetic Logic Unit
(ALU), and control unit.
Central Processing Unit
controls the operations of the entire computer system
CONTROL UNIT
________ executes the instructions and performs all the
calculations and decisions.
The Arithmetic Logic Unit (ALU
This is also called as Main Memory. Before the actual processing starts the data
and the instructions fed to the computer through the input units are stored in this
primary storage unit.
The Primary Storage Unit
The output devices give the results of the process and computations to the
outside world. The output units accept the results produced by the computer, convert
them into a human-readable form, and supply them to the users. The more common
output devices are printers, plotters, display screens, magnetic tape drives, etc.
Output Unit
It facilitates the remembrance power to computer system. It refers to the
physical devices used to store programs (sequences of instructions) or data (e.g. program
state information) on a temporary or permanent basis for use in a computer or other digital
electronic device.
MEMORY
Memory can be of two types:-
. Primary Memory
2. Secondary Memory
The term primary memory is used for the information in physical systems which are fast
(i.e. RAM), as a distinction from secondary memory, which are physical devices for
program and data storage which are slow to access but offer higher memory capacity.
Primary memory stored on secondary memory is called virtual memory.
KEY CONCEPTS
PRIMARY- FAST
SECONDARY- SLOW
PRIMARY MEMORY STORED ON SECONDARY IS CALLED- VIRTUAL MEMORY
Primary Memory can be categorized as:-
- Volatile Memory (RAM)
- Non-Volatile Memory(ROM)
_____– is computer memory that requires power to maintain the stored
information.
Volatile memory
RAM stands for
Random Access Memory
It can be of two types OF VOLATILE
- Static RAM or SRAM.
- Dynamic RAM or DRAM
retains its contents as long as the power is connected and is easy to interface to
but uses six transistors per bit.
SRAM
is more complicated to interface to and control and needs regular refresh
cycles to prevent its contents being lost. However, DRAM uses only one transistor and a
capacitor per bit, allowing it to reach much higher densities and, with more bits on a
memory chip, be much cheaper per bit.
Dynamic RAM
