RAM, which stands for Random Access Memory is the best known form of computer memory. The memory is regarded as “Random Access” because one may access any memory cell directly provided the row and the column that intersect that cell are known. Most people when they refer to “computer memory” actually are referring to RAM, even though they may not fully appreciate the fact. RAM takes the form of integrated circuits that permit the stored information to be accessed on any order. Contrast this mechanism and the one found in audio tapes, magnetic or optical discs. These media rely on the movement of either themselves or the reading apparatus for data transfer making it a slow process. RAM standard modules for a desktop computer are long, thin apparatuses that look like short rulers. The bottom edges of the memory modules have notches to guide installation and are lined with gold-plated connectors. Many new desktop come with at least 256 megabytes (MB) of RAM installed, though this can be upgraded to 512MB or even more than 1GB. The more RAM a computer has the less number of times the Central Processing Unit (or CPU) must read data from the hard disc, making the computer operate at a much faster rate than the one with low RAM.
RAM is volatile memory, and this means that once the computer is turned off, the information stored in the RAM disappears. When the computer is turned on again, the PC’s boot firmware that is called BIOS (for Basic Input/output System) uses the instructions on the ROM (Read Only Memory) to read the operating system and related files from the disc and load them on RAM. Some parts of the may be more easily accessible to programs. For instance, cache RAM has very high speed RAM chips that lie between the CPU and the main RAM and stores (technically, Caches) memory accesses by the CPU. This high speed RAM is usually made up static RAM chips, whereby a form of flop-flip holds each bit of memory and never has to be refreshed. But static RAM is more expensive than, say dynamic Random Access Memory since it takes up more space on a chip.
There are many types of RAM and below are just examples of some of them.
· SRAM- This stands for Static Random Access memory that has multiple transistors, from four to about six. It is usually used in caching.
· DRAM-This stands for Dynamic Random Access memory. They have memory cells and a pair of transistors and capacitors requiring to be refreshed constantly.
· FPM DRAM- This is the ellipsis for Fast page mode dynamic random access memory, which was the original version of DRAM.
· SDRAM- Stands for Synchronous dynamic random access memory. It stays on the row that has the requested bit and it goes swiftly along the columns reading many bits as it moves on. This concept greatly improves performance, which explains why it is the most common form of RAM found in many desktops today.
· Credit Card Memory-credit cards have DRAM memory embedded in them as well.
For more information on RAM read What is RAM?
