Where the information is stored. Memory is organized in little cubbyholes, each of which needs an address. These cubbyholes have memory structure that is separated into Bytes. These bytes and how much they amount in text
One byte of computer memory can store one character. For example the word LOVE will occupy four bytes of memory or disk space.
· One Kilobyte (KB) is approximately one thousand bytes.
· One Megabyte (MB) is approximately one million bytes.
· One Gigabyte (GB) is approximately one billion bytes.
· 1 KB = 1000 bytes
· 1MB = 1, 000,000 bytes or 1,000 KB
· 1 GB = 1,000,000,000 or 1,000 MB or 1,000,000 KB
a) RAM: Random Access Memory stores programs and data as it is used. The info in RAM is lost when the power is turned off. Info can be written to and read from RAM. A modern computer usually has from 64 to 256 MB (Megabytes) of RAM.
b) ROM: Read Only Memory stores start up and basic operating info. Info can be read from, but not written to ROM. The info in ROM is not lost when the power is turned off. Computers generally have about 400-500 KB (Kilobytes) of ROM.
c) Power On Self-Test: POST is a program stored in ROM that the computer "wakes up" asking for. This program tests the computer and makes it ready to start.
d) Basic Input Output System: The BIOS a collection of little programs to run the most basic things in the computer, such as draw a character on the screen; check the memory, read the disk, read the keyboard, etc.
e) Video Memory holds the information that is presently being displayed on the monitor. The data here is usually in a different form than that in the RAM because it has been translated into the patterns of dots that we interpret as words, pictures, etc. Most computers have 8-32 MB of video memory.
Figure 5. Computer Memory Pyramid