Computer Connectors and Cable

Internal Connectors

Several types of cables are used to connect components together inside the case, providing power and a path for data. These include:

1. Motherboard Power Connector: This connector is designed especially to move electricity from the power supply to the motherboard. Older computers use the AT power connections, with two six-pin connectors lined up side by side. ATX motherboards used a single connector with 20 pins arranged in two rows of 10.

Many motherboards now also use supplementary power connectors, such as a 4 pin plug specifically for the CPU supply.

Some others have more than 20 pins for the main connector. The extra pins are in the form of a 'separate' connector, that fits onto the end of the standard 20 pin connector. This may be used or not as required by the particular motherboard.

The PCI-e interface may also require the use of further power cables from the power supply.

2. Power Connectors for Drives: Hard drives, optical drives, and, increasingly, high-end video cards use a 4-wire power connection, of which several are available from a power supply. Floppy drives use a smaller connector.

With the introduction of the SATA interface for data another type of power connector for drives was also introduced. This is thinner than the previous power connector.

3. 40 and 80-pin IDE Cables: These cables are used by hard drives and optical drives to transfer data to and from the motherboard. These are now sometimes called PATA (Parallel ATA) cables to differentiate from the more recent SATA.

4. SATA (Serial ATA) Cables: These cables are now used by most hard drives and even optical drives to carry data to and from the motherboard. They are much thinner than SATA ribbon cables, and the connectors are much smaller. Generally red coloured.

SATA drives generally also require a new type of power connector, though some can also use the older white 'Molex' plug. Adaptors are available if the power supply doesn't have the correct connector.

5. 34-pin Floppy Cables: These are used to connect floppy drives to floppy disk connectors on the mainboard/motherboard.

External Connectors

Without connections to the rest of the world, a computer would just be a fancy paperweight. Numerous connectors are used to make a computer useful.

6. AT Keyboard Connector: Found on older computers, this connector is large and round with five pins.

7. PS/2 Connector: This connector is currently the most popular for connecting both the keyboard and mouse. Note that older mice once used serial ports (defined below), and newer mice frequently use the Universal Serial Bus (USB).