Interface And Ports

Peripherals are devices that are attached to a computer system to enhance its capabilities. Peripherals include input devices, output devices, storage devices, communication devices. All peripherals must have some way to access the data bus of computer. To do this, peripherals are connected by ports.

A port is a socket on the outside of the system unit that is connected to an expansion boards on the inside of the system unit.

Parallel Ports

A parallel port allows to lines to be connected that will enable 8 bits to be transmitted simultaneously. Parallel lines moves information faster than serial lines do, but they can transmit information efficiently only up to 15 feet. They, parallel ports are used principally, for faster sped devices such as connecting printers. It has 25 pins.

Serial Ports

A serial port, or RS-232 port, enables a line to be connected that will send bits one after the other on a single line. Serial lines are used to link slow speed devices and equipment that is not closed by serial ports are used principally for communication lines, modems and mice. It has 9 pins.

USB (Universal Serial Bus)

USB is a newer type of serial connection that is much faster than the old serial ports. USB is also much smarter and more versatile since it allows the “daisy chaining” of up to 127 USB peripherals connected to one port. USB ports can supply the connection of many kinds of devices such as Keyboard, mouse, printer, memory card etc. New PCs and Macs include several USB ports.

IEEE-1394 Interface (Fire-Wire Ports)

The IEEE -1394 interface is a serial bus standard for high speed communications and isochronous real –time data transfer , frequently used by personal computers as well as in digital audio , digital video and aeronautics applications. It replaced parallel SCSI in many applications, because of lower implementation cost and a simplified, more adaptable cabling system.

SCSI (Small computer System Interface) Port

Pronounced “scuzzy” a SCSI port provides an interface for transferring data at higher speeds up to eight SCSI-compatible devices. These devices include external hard disk drives, magnetic-tape backup units, and CD-ROMS devices.

Peripheral componets Interconnect (PCI) slot

Conventional PCI is a computer bus for attaching hardware devices. These devices can take either the form of an integrated circuit fitted onto the motherboard itself, called a planner device in the PCI specification or an expansion card that fits into a socket. PCI slot is in PC to connect device like network cards, sound cards, internal modems etc.