In a computer conversation, an computer Bus, also called a processor bus, front bus, front bus, or rear bus, is a group of electrical wires used to send information (data) between two or more components. For example, the Intel processor on the current Mac line uses a 64-bit data bus to connect the processor to its memory.
A data bus has many different defining characteristics, but one of the most important is its width. The width of the information bus refers to the number of bits (electrical wires) that make up the bus. Total data bus widths include 1-, 4-, 8-, 16-, 32-, and 64-bit.
When manufacturers specify the number of bits that a processor uses, such as “This computer uses a 64-bit processor,” they refer to the width of the data bus on the front that connects the processor to its main memory. Other types of data buses used in computers include a rear bus that connects the processor to the stored cache.
The data circuit is usually controlled by a bus controller that regulates the speed of information between components. Usually everything has to run at the same speed in the computer and nothing can move faster than the CPU. Block controllers keep things moving at the same speed.
Early Macs uses a 16-bit data bus; the original Macintosh used a Motorola 68000 processor. Newer Macs use 32- or 64-bit buses.
Types of buses
A data bus can operate as a serial or parallel bus. Serial buses – such as USB and FireWire – use a single cable to send and receive information between components. Parallel buses – such as SCSI connections – use many cables to communicate between components. These buses can be internal to the processor or external , with respect to a component that is connected.