RAM
RAM means Random Access Memory. It is a “temporary” memory that is lost when the system shuts down, hence the “random” part of the name since any piece of information can be circulated through the memory regardless of its location and its relation to any other information.
The first RAM was created in 1951 and was used until the late 1960s and early 1970s.
RAM Types
Some types of RAMs used today are: SRAMs (static RAMs), which stores data in a state of a flip-flop, or DRAMs (dynamic RAMs), Flash, and EPROM, which store data as a charge in a capacitor.
A ROM, is a type of a RAM that has permanently enabled/disabled selected transistors by using a metal mask. ROMs thus cannot store any further charges.
Flash memory is widely used because SRAMs and DRAMs are known to be highly volatile, so new products adopt the flash memory technology. Portable music players, scientific calculators, mobile phones, are devices that use flash memory.
There are two types of flash memory: the NOR type is able to conduct a random access, and is widely used as a ROM and the NAND type used in flash USB drives.
RAMs are shipped as DRAM modules or memory modules. The Plug n Play technology, allows the user to easily replace them by taking the old one out of the port and replacing it with a new one. There is also an extremely small amount of RAM (known as SRAMs) within CPUs, motherboards, and hard drives.
RAM Swapping and Thrashing
Sometimes the computer will conduct a task known as swapping. This is when the computer uses the hard drive space in place of the memory temporarily. Constantly swapping is called thrashing, but as the name suggests, constant thrashing can decrease system performance.
Security
SDRAMs are not fully shut off when the power is cut. The stored memory is faded away, this takes seconds in a normal room temperature, and can take up to minutes in lower temperatures. Encrypted information could potentially be leaked while it is still stored in the memory.
Recent Developments
Non-volatile RAMs are under development, so that memory can still be stored when the power is shut off. In 2004 Nantero developed a fully functioning carbon nanotube memory type holding 10 GB. In 2006, “Solid State Drives” with sizes of 150 GB and a faster speed have been created.
