The Computer Revolution/Hardware/Memory

From Wikibooks, open books for an open world
Jump to navigation Jump to search

Types of Memory[edit | edit source]

4 types of Memory

1.RAM[edit | edit source]

So what is RAM Memory?

Basically Ram, or random access memory, temporarily stores both software instruction and data. It is stored both before and after it is processed by the CPU. It is basically your computers short term memory.

RAM, is only temporarily memory, as it requires electricity to maintain the information stored in it. Hence, once the power is off the information is gone. Because of this, RAM is also been dubbed the Volatile storage area.

RAM is just like CPU, it also contains the electronic circuits etched onto chips, which in turn, are plugged to motherboard, hence called memory modules. Every computer is installed with different memory modules, like desktop and servers computer use dual in line memory modules whereas notebooks use small version memory modules namely small outline DIMM or SO-DIMM. In addition to that, many personal computers today are installed with two to four slots among them one will always be filled, but other slots are always available to install additional memory modules to it; to increase the performance of the computer.

Ram is measured in megabytes. Most computers today provide at least 256MB of RAM memory... of course this can be increased. The easiest way to tell if you overloading your RAM memory is to open several applications at the same time and run each. The response rate ( quickness) on how the applications respond from your inputs, will give you and idea of the amount of information your RAM can handle at any one time.... The more programs or applications running the slower the response.. Reason for this is that once the RAM becomes overloaded, the software will then start running applications off your hard drive which of course slows the overall performance of the computer.

There are 4 types of RAM Memory:

  1. DRAM - Dynamic RAM
  2. SDRAM - Synchronous Dynamic Ram
  3. SRAM - Static Ram
  4. DDR-SDRAM - Double date rate synchronous dynamic ram

By Kris Lobsinger

2.ROM[edit | edit source]

Primitive ROM from a vintage IBM-26 Keypunch Machine

ROM meaning Read-Only Memory is memory whose contents can be accessed and read but can't be changed. It is mainly used in computers but it is also used in other electronic devices. Since it can't really be written to, its main use is the distribution of Firmware. ROM is in the shape of a "computer chip". It can only be read with the exception of being written on once during the step called "programming". ROM's also cannot be erased or re-programmed. There are many different types of ROM including PROM's(Programmable Read-Only Memory). ROM is measured in Megabytes.

These nonvolatile chips are attached to the motherboard inside the system unit. ROM chips store the permanent instructions for the computer (also known as firmware) and the information stored here is retrieved as needed by the computer. Being nonvolatile, the information is not lost once the computer has been shut off.

ROM would include such things as the computer's BIOS (basic input/output system), which are the instructions the computer follows for booting up. It would also include directions for performing a POST (power-on self-test). Neither the BIOS nor the POST can be updated in traditional ROM. However, with the advent of flash memory and its replacing of traditional ROM, these operations can now be updated during the life of the device.

References: Morley, Deborah and Charles Parker, Understanding Computers Today and Tomorrow, 13th Edition

3.CMOS[edit | edit source]

Also known as a RTC/NVRAM or CMOS RAM, CMOS is short for Complementary Metal-Oxide Semiconductor. CMOS is an on-board semiconductor chip powered by a CMOS battery inside IBM compatible computers that stores information such as the system time and system settings for your computer. A CMOS is similar to the Apple Macintosh computer's PRAM.

Flash memory is the most common type of storage for portable devices such as digital cameras and phones. It can be used to transfer data from one device to another, and most computers today come with a flash memory card reader. Secure Digital (SD) is one of the most widely used flash memory media and it comes in different sizes. The standard size are generally used for cameras, and the miniSD and microSD are generally used for cell phones, and are about one quarter to one half the size of the standard SD card. There are adapters available for the smaller sized SD cards so they can be used in the standard flash memory card reader. The capacity for these cards is growing and is up to 4 GB for standard cards and 32 GB for high-capacity cards.

Flash Memory Cards

4. Flash[edit | edit source]

Flash memory- is a form of non-volatile computer memory that can be electrically erased and reprogrammed.

Flash memory is available in 3 forms: 1. Flash memory card (aka RAM cards)- Removable storage media that is inserted into a flash memory port. It retains data when the power is turned off. 2. Flash memory sticks- Flash memory that plugs into a memory stick port which is very convenient to transport and use. 3. Flash Memory drives- finger sized module of flash memory that plugs into the USB ports of nearly any PC or Mac.


As the ever quickening world of technology grows, new hardware is being demanded. RAM that we know now is volatile. When power is cut to the computer, data isn't retained in RAM. New methods are under development of nonvolatile RAM where data will continue to be held while no power is being supplied. Magnetic RAM is on the threshold of becoming very useful. It uses magnetic polarization to store information.

Media Memory Card

Flash memory is a nonvolatile chip that is used for storing items from a computer or from a user. This can also be easily erased and rewritten as often as needed. They are built into all types of technology devices, like cell phones, cameras, portable computers and IPods. Flash memory can come in different sizes. The most common GB people purchase is 1GB, 2GB, 4GB, 8GB, 16GB, and 32GB.

USB Flash Drive

Flash Memory Drives or USB flash drives are a portable storage device that use a type of electronic memory called flash memory. Flash memory is referred to as solid-state, meaning that what makes it work is electronic and not mechanical. Flash drives can be used to back-up/store information such as text documents and pictures. They are compatible with a variety of devices from computers to digital cameras and even video game systems! Flash drives are a convenient and fairly inexpensive mode for storing information and allowing the user to take important data with them for use wherever they made need it.