Motherboard
several layers, printed cuircuit board.
Expansion boards
(also called interface cards, adapter cards) are circuit boards (small motherboards),
which are put into the expansion slots in the motherboard. Examples:
- Sound card,
- Video card (graphics card),
- Modem card (internal modem),
- Network card
- PC cards (credit-card sized) and Flash memory cards are special expansion
boards for notebooks.
Newer motherboards may already include video and sound functions.
Ports and Connectors
=points where a peripheral device is plugged into the system unit. Connectors
(which may be male or female) are what you plug into the port. Ports can be
serial (one bit at a time) or parallel (many bits at a time, faster
but less reliable, used for printers, for instance). Some often used ports are:
- USB: (Universal Serial Bus): can be connected over each other, hot-swappable,
convenient.
- FireWire: for faster transmission, like for videos.
- Midi port: Serial, connects the computer to electronic keyboards.
- SCSI port: (small computer system interface), parallel, high speed, for
disk drives or printers.
- IrDA port: for infrared light.
- Bluetooth ports: for radio wave transmission.
Buses
for transfering data, consist of data bus (for transmitting data) and address
bus (for information where to find the data). The bus width tells how many bits
can travel per time unit, the number of time units per second of the bus is
measured by the clock speed.
System Bus
between CPU and memory
Expansion buses
connection to peripheral devices.
- ISA (Industry Standard Architecture): for mouse or modem, slow
- PCI (peripheral Component Interconnect): high speed, for hard disks and
network cards
- AGP accelerated Graphics Port, between memory and graphics card,
- USB bus, FireWire bus, PC Card bus.
