How Computers Represent Data
Computer data is reduced to binary numbers because computer processing is performed by transistors that have only two possible states: ON and OFF. The binary number system works the same way as the decimal system, except that it has only two available symbols (0 and 1) rather than ten (0, 1, 2, 3, 4, 5, 6, 7, 8, and 9). A single unit of data is called a bit; 8 bits make up 1 Byte. In the most common text-code set, ASCII, each character consists of 1 Byte of data.
How Computers Process Data
A microcomputer's processing takes place in the central processing unit, the two main parts of which are the CONTROL UNIT and the ARITHMETIC LOGIC UNIT (ALU). The CPU follows a set of steps for each instruction it carries out. many CPUs can process more than one instruction at a time.
Random Access Memory (RAM) is volatile (or temporary). Programs and data can be written to and erased from RAM as needed. The amount of RAM can affect speed because the CPU can keep more of the active program and data in memory, which is faster than storage on disk.
Read-only memory (ROM) is nonvolatile (or permanent). It holds instructions that run the computer when the power is first turned on.