- Ports
- Expansion Slots and Boards
Ports:
- External devices-such as those used for input and output-are connected to the system by ports on the back of the computer.
- PC`s feature a number of built-in ports,which are ready to accept devices such as printer,mouse,keyboard,phone line,microphone and speakers and others
- Most computers come with a serial port and a parallel port.A serial port transmits one bit of data at a time;a parallel port transmits data one byte at a time.
Expansion Slots and Boards:
- If the PC does not have a port for an external device,we can install an expansion board into one of the empty expansion slots.
- A board provides the correct port for the new device, and connects the device to the CPU by way of the computers expansion bus.
- Newer bus technologies such as Universal Serial Bus(USB)and IEEE 1394 enable many devices to be connected to one port.
- Small computer system Interface(SCSI) is an older standard for extending the bus to multiple devices through a single port.
