COMPUTER MEMORY PRESENTATION BY NIKUNJ PATEL
May 22, 2015
COMPUTER MEMORY
PRESENTATION BY NIKUNJ PATEL
HISTORY OF
MEMORY
HISTORY OF MEMORY
In the early 1940s, memory technology mostly permitted a capacity of a few bytes.
ENIAC(Electronic Numerical Integrator And Computer): Firs electronic general-purpose computer .
That is capable of being reprogrammed to
solve a large class of numerical problems.
DELAY LINE
MEMORY
DELAY LINE MEMORY
developed by J. Presper Eckert in the early 1940s.
It is also used in digital computers.
Delay line memory would be limited to a capacity of up to a few hundred thousand bits to remain efficient.
RANDOM ACCESS COMPUTER MEMORY
RANDOM ACCESS COMPUTER MEMORY
The Williams tube and Selectron tube originated in 1946.
In 1947 Jay Forrester, Jan A. Rajchman and An Wang developed magnetic core memory which allowed for recall of memory after power loss.
The Selectron was limited to 256 bits, while the Williams tube could store thousands
RANDOM ACCESS COMPUTER MEMORY
MAGNETIC CORE
MEMORY
MAGNETIC CORE MEMORY
It was the computer memory of choice throughout the 1960s, until it was replaced by semiconductor memory.
MEMORY
MEMORY It holds the data and instructions that the
Central Processing Unit (CPU) needs.
Before a program can be run the program is loaded from the storage medium into memory.
It allows the CPU to direct interact with the program.
Memory is a need of every computer
TYPES OF MEMORY
TYPES OF MEMORY
ROM (Read Only Memory)
RAM (Random Access Memory)
Cache memory
Flash memory
READ ONLY MEMORY
stores data without electrical current; it is the ROM (Read Only Memory)
or is sometimes called non-volatile memory as it is not erased when the system is switched off
RAM
Random Access Memory, can be accessed randomly. Any byte of memory can be accessed without touching the preceding bytes. RAM is the most common type of memory found in computers and other devices, such as printers.
DDR2 RAM & DDR3 RAM
TYPES OF RAM
TYPES OF RAM
There are two different types of RAM:
DRAM (Dynamic Random Access Memory)
SRAM (Static Random Access Memory).
DRAM Needs to be refreshed thousands of times
per second while. Dynamic RAM needs to automatically
refresh thousands of times per second; that's where it gets the name dynamic. Otherwise, it will forget the information it's holding.
SRAM
Does not need to be refreshed, which is what makes it faster than DRAM.
Both types of RAM are volatile, meaning that they lose their contents when the power is turned off.
CACHE MEMORY
CACHE MEMORY
The cache is a smaller, faster memory which stores copies of the data from frequently used main memory locations.
FLASH MEMORY
FLASH MEMORY
Non volatile memory can be erased electronically and rewritten similar to EEPROM.
Introduced by Toshiba in 1984.
Most computers use it to hold up their startup instructions.
Also used in many mobiles , smart phones , digital cameras and PDA.
FLASH MEMORY
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