SECONDARY MEMORY DEVICES
. TWO TYPES OF MEMORY ARE:
1. Primary memory.
2. Secondary memory.
1. PRIMARY MEMORY:
Primary memory what they also called internal storage or main storage. The Primary storage is a computer memory that accesses first. It is runtime execution services and applications stored temporarily in a specific memory location. They are two types of primary memory RAM(Random Access Memory) and ROM (Read Only Memory).
RAM (Random Access Memory):
Ram (Random Access Memory) is an internal memory that is which cache to hold data short team storage that can be stored in recently used applications, data, and programs in the RAM. The RAM is unstabled because, When the power supply is cut off the computer or laptop data stored in the ram will get lost or when the power supply is cut off.
.Two types of RAM are :
SRAM (Static Random Access Memory) is an unstable memory; data is lost when the power supply is cut off. SRAM chips used a matrix of 6-transistors and no capacitors. Transistors don't request power to prevent leakage, So do not need to refresh on regular basis. It's faster than DRAM
DRAM(Dynamic Random Access Memory ) wants to continue to refresh in order to maintain the data. This is done by placing the memory on the refresh circuit that rewrites the data several hundred times per second.
ROM (Read Only Memory):
ROM (Read Only Memory) is a type of computer storage that is non-unstable, it is read only not to write. The advantage is the applications, data, and programs are stored on the hard disk so when the power supply is cut off the data won't be lost or forgotten.
. Two types of ROM are :
Capacity media is an inside Secondary medium like a hard circle that is fixed inside the PC. A Storage medium that is convenient and can be taken external the PC is named removable storage media. It can store permanently for long-time stored of data and programs.
ExamplesMROM (Mask Read Only Memory) One of the rom type of hardware memory devices that pre-program in the time of manufacturing the device and it can't re-write the program or erasable. The MROM is an old rom there not used in day today's life.
PEROM (Programmable Read Only Memory) is a special type of rom that can be reprogrammable after the manufacturer and also the user can buy the rom and write the program independently. An illustration of a PROM is a PC Profiles in early PCs. Today, PROM in PCs has been supplanted by EEPROM. At the point when the PROM is made, all pieces read as "1" . During the programming, any cycle waiting to be changed to a "0" is carved or consumed into the chip utilizing a pack software engineer.
EPROM (Erasable Programmable Read Only Memory) is a type of programmable read-only memory. The EPROM will be erased when the power supply is cut off. It is exposing it to ultraviolet light and it could not be erased electrically.
EEPROM (Electrically Erasable Programmable Read Only Memory) is known as a type of data stored in a device or computer called Electrically Erasable Programmable Read Only Memory. It is cabal to erase and re-programmable. However, is individual bytes of data can erase and re-programmable but not specifically by the electrical voltage. Most EEPROM chips have a life expectancy of 10,000 to 100,000 compose cycles, which is impressively more prominent than the compose patterns of EPROM chips.
2. SECONDARY MEMORY:
Secondary memory is an external storage device in the computer. It permits clients to store information and data that can be recovered, sent, and utilized by applications and administrations rapidly and without any problem. The Secondary storage media can be fixed or removable. Fixed
. SOLID-STATE DRIVES(SSDs)
. HARD DISKS (HDDs)
. CD-ROM
. DVD DRIVES
. USB FLASH DRIVES
. BLU-RAY DRIVES
. SD CARDS
. FLOPPY DISKETTE
. TAPE DRIVES
. CLOUD STORAGES