STORAGE MEDIA

DDR is abbreviated as a double data rate.

DIMA is abbreviated as a dual in line memory. The speed and capacity will be change with our
requirement and cost not fixed , in the chart it was max or temp.

MEMORY

The term memory refers to a chip that stores data.It also enables us to retrieve the stored data. The processor retrieves information stored in the memory for processing.

MEMORY:

            Memory is one of the functions of the brain that enables to store and remember the past events. Similarly, in computers

TYPES OF MEMORY:

 Memory can be divided into mainly two types:

Volatile memory:

It stores the data temporarily. It loses the data as soon as the system supply is turned off. Most forms of modern Random Access Memory (RAM) are volatile storage, including Dynamic Random Access Memory (DRAM) and Static Random Access Memory (SRAM).

Non-volatile memory:

            It stores the data permanently. It does not lose the data even if the system supply is turned off. Non-volatile memory is typically used for the task of secondary storage, or long-term persistent storage. Non-volatile data storage can be categorized in electrically addressed systems (Read Only Memory) and mechanically addressed systems (Hard disks, Optical discs, Magnetic Tapes).

PHYSICAL MEMORY:

            Physical memory is the total amount of memory installed in the computer. It is the only one directly accessible to the CPU. The CPU continuously reads instructions stored there and executes them as required. For example, if the computer has two 1GB memory modules installed, it has a total of 2GB of physical memory.

The different types of physical memory are:

            RAM:

RAM stands for Random Access Memory. It is a semiconductor-based memory where the CPU or the other hardware devices can read and write the data. It temporarily stores and it is a volatile memory. Once the system is turned off, it loses the data. As a result, RAM is used as temporary data storage.

ROM:

            ROM stands for Read Only Memory. It stores the data permanently and it is a non-volatile memory. It does not lose the data even after the system turns off. As a result, ROM is a permanent data storage area.

The different types of ROM are:

      PROM: It stands for Programmable Random-Only Memory. It is also known as One Time Programmable (OTP) chips. It stores programs permanently and is a non-volatile memory. Programming the ROM is sometimes referred as burning and it requires a special machine called a Device Programmer or ROM Burner.

       EPROM: It stands for Erasable Programmable Read-Only Memory. Ultra-violet (UV) rays can remove the programs from this memory. It can be easily recognized by the clear quartz crystal window set on the top of chip. An EPROM eraser is a device that contains a UV light source that erases the chip by causing a chemical reaction, which essentially melts the fuses back together.

        EEPROM/Flash ROM: It stands for the Electrically Erasable Programmable Read-Only Memory. Electrical signal removes the programs from this memory. EEPROM can be erased by an electric field, rather than exposed to UV. Also, the data can be erased bit by bit allowing only selected portions of the code to be replaced. This is also called Hybrid memory as it reads and writes data similar to the RAM but, maintains data similar to the ROM. It is a mixture of RAM and ROM.