The computer’s bulk of work is concentrated on its CPU and here is where the computer memory is located. You can consider the computer memory as the brain that processes the information being put in by the computer user.

Computer Memory

As the CPU processes information, it sometimes needs to store information for later use or to find information that was previously stored. Memory devices provide a means of doing that. There are many different types of memory devices, each filling a different need.

Internal Memory

A computer’s internal memory is part of the CPU itself. As the CPU does its job, it must have ready access to much of the information with which it is working. That information is stored in internal memory. For efficient data processing, internal memory must meet certain requirements.

First, internal memory must be fast; information must move quickly between it and the microprocessor (the chip that carries out the instructions of the program). Second, information in any part of the memory must be as accessible as any other. Since the computer can run so many programs, it must be possible to gain access to a random series of memory locations for either storing or retrieval of information.

To satisfy those requirements, internal computer memories are composed of several random-access memory, or RAM chips. For speed of information transfer, RAM chips are usually located very close to the microprocessor.

When people speak of a computer’s information storage capacity, they mean the number of bytes (pieces of information) contained in its RAM chips. For personal computers, RAM size is usually measured in kilobytes, abbreviated as K. Kilo is Greek for 1,000. A computer with 64 K of RAM has 65,536 bytes of internal random-access memory. Larger computers have memory measured in tens or hundreds of megabytes, abbreviated as M. Mega means 1,000,000, although one M is actually slightly more, since it is 1 K times 1 K. Computers with gigabytes of internal memories are definitely much faster. 1 G equals 1 K times 1 M, or about 1,000,000,000 (billion).

Most RAM chips have one major drawback: their information disappears when the power is turned off. Therefore computer memories also contain a few read-only memory, or ROM chips to store information that is always or almost always needed when the computer is running. Computers have a start-up ROM that contains the very first instructions the computer must follow in order to begin operating. Many personal computers also have a ROM chip enabling them to run programs in a certain programming language.