Everything in a computer’s memory takes the form of binary digits (BITS). Each one is stored in a memory cell that can have two values, zero and one. Files and programs are comprised of these bits and are processed in the central processing unit, CPU, which is the computer’s ‘brain.’ Like a human’s, it has both long-term, to store things permanently, and short-term memory, for immediate tasks. These two types of computer memory are:
Random Access Memory (RAM) – This acts as a system’s short-term memory, from which it can quickly access data. This data is lost when the device shuts down, however. RAM is also responsible for our ability to run programs, through which data can be retrieved and modified, or new data made. The length of time it takes for the system to do this is called the memory’s ‘latency.’ To process and access data quickly, the information can be retrieved in any order. The data only remains in the RAM while the device is on.
Dynamic RAM (D-RAM) is the most common type of RAM, in which each memory cell consists of a transmitter and a capacitor to store electrical charges. The memory is referred to as dynamic because it is only held briefly before it leaks away and needs to be charged periodically to retain data.
Another type of RAM is Static RAM (S-RAM), which is made up of 6 interlocking transistors that don’t need to be refreshed. S-RAM is the fastest memory in a computer system.
Read Only Memory (ROM) – This is a system’s long-term memory and is responsible for the booting up of devices. Data must be stored in a device’s ROM to be kept long-term. There are currently three types of ROM, which all have less than a ten-year storage guarantee because of the breakdown of the materials used.
The cheapest and most common is magnetic storage, which imprints data on a disc coated with magnetic film.
Optic storage, such as DVDs, is a second option and encodes BITS as light and dark spots, which are read by a laser.
Solid state drives, such as USB drives, are the newest and fastest long-term storage option. These use floating gate transistors to store BITS, by trapping or removing electrical charges within their internal structures.
The number of BITS that need to be stored is growing continuously, and scientists are trying to develop other cost-effective ways to store them. This includes making memory devices at the quantum level to ensure that they are faster, smaller and more durable. Scientists from Fudan University, in Shanghai, have published a study in Nature Nanotechnology detailing a type of computer memory that can perform both long and short-term memory functions. The technology would also let the user decide how long the data should be stored for, creating enhanced features and bespoke devices. Researchers are currently unsure when the product will be debuted, but anticipate it becoming a serious competitor against RAM and ROM.