Thursday, 4 July 2013

Ports and Connectors

Legacy Multifunction Ports

9-pin and 25-pin serial port use for connecting serial devices to the computer. 25-pin parallel port use for connecting parallel devices to the computer. Serial devices transfer data 1 bit at time. Parallel devices transfer data 8 bit at a time.

Standard Single-Function Ports

Keyboards connect to the motherboard with 6-pin mini-DIN (PS/2) or USB connectors. Mice connect to 9-pin serial bus in older systems, and PS/2 or USB in newer systems. 15-pin, three-row D-sub port is for video. 15-pin, two-row D-sub port is for MIDI devices or joystick. Know the difference between the RJ-11 connectors for modems and RJ-45 connectors for NICs.

Modern Multifunction Ports

USB enables you to hot-swap devices and daisy-chain up to a single USB port. The Type A connector goes into USB port; the Type B or mini connector goes into the USB devices. USB (aka normal USB 1.1) is capable of throughout speeds up to 12Mbps, while Hi-Speed USB is good for up to 480Mbps.

IEEE 1394 is also known as FireWire, iLink, and Lynx. Either IEEEa (400 Mbps) or IEEE 1394b (800 Mbps) enables you to connect up to 63 devices to a single IEEE 1394 port.

Finally, many SCSI technologies today use 68-pin ports by ultra-320 devices. You may also see 50-pin, 25-pin or other varieties.