Before you start
Objectives: learn how common connectors look like, what do we call them and what are they used for. We have another article in which we discuss video ports and connectors in detail.
Prerequisites: no prerequisites
Key terms: connector, port, mouse, keyboard, serial, parallel, spdif, network, rj-45, rj-11, network, phone line, audio, vga, db-15, s-video, dvi, analog, digital, firewire, usb,
Mouse and Keyboard Connectors
Mouse and keyboard connectors are called Mini-DIN connectors. They are also often called PS/2 because these were the type of ports IBM invented for their PS/2 line of computers. The green Mini-DIN is used to connect the mouse and the purple one is used to connect the keyboard. Most PC manufacturers will follow that convention. There is also one other convention which says that the mouse connector goes on top, and the keyboard connector goes on the bottom. This convention is used when the connectors are not colored in green and purple. Older systems used larger connectors called DIN connectors.
Image 135.1 – MIni DIN
Serial port uses the DB-9 connector (9 pins, D shape). This connector is used to connect serial devices to the PC, such as a mouse, modem or even a serial printer.
Image 135.1 – Serial
Parallel connector uses a DB-25 connector (25 pins, D shape). It is used to connect parallel devices with the PC such as a printer, scanner or even external hard drive.
Image 135.3 – Parallel
S/PDIF stands for Sony/Philips Digital Interface. This interface is used to transfer audio, and it can be designed for coaxial cable or optical cable.
Image 135.4 – S/PDIF
Over the years various types of network connectors have been used in PC systems. Today the most popular type of network is an ethernet network. Therefore many motherboards have those connectors implemented. The ethernet network connector uses an RJ-45 socket.
Image 135.5 – RJ-45
Phone line connector is used to connect dial-up modems with phone lines. It is also called RJ-11.
Image 135.6 – Modem
USB allows us to connect a variety of external devices. We can connect up to 127 devices using series of USB hubs. We can connect printers, digital cameras, external hard drives, TV tuners, and many other devices.
Image 135.7 – USB
The next is the audio interface. On most systems we will always see the Line-in connector which we can use for connecting external audio source (blue). We will also see the green connector which is the Line-out connector. That connector is used to connect speakers to our PC system. The last connector, usually pink one, is the Microphone jack. We can use it to record audio from the microphone. The colors that we mentioned here (blue, green and pink) are fairly well standardized in the PC industry. If some other colors are used, then those connectors are usually labeled. On some motherboards we can even have more audio connectors which are then multiple channels. For example, Dolby audio uses black connector for rear speaker and orange connector for subwoofer.
Image 135.8 – Audio
>The first video connector that we will mention is the DB-15 connector. This DB connector has three rows and we can recognize it because of that. It is usually called a VGA connector.
Image 135.9 – VGA
Some motherboards can also have s-video connector. We can use it to connect our PC to the TV.
Image 135.10 – S-Video
The third video connector is the DVI connector. That connector is used to connect digital monitors to the PC. VGA monitors are actually analog monitors. We had to convert digital signal from the PC into an analog signal for the monitor to display. DVI connector allows us to take that digital signal and send it to a digital monitor right away.
Image 135.11 – DVI
The next connector is the IEEE 1394, also known as the FireWire port. FireWire functions much in the same fashion as a USB. It is used to connect things like digital cameras, external hard drives, scanners and others.
Image 135.12 – FireWire
Mouse and keyboard connectors are called Mini-DIN or PS/2 connectors. The green Mini-DIN is used to connect the mouse and the purple one is used to connect the keyboard. Serial port uses the DB-9 connector (9 pins, D shape). Parallel connector uses a DB-25 connector (25 pins, D shape). S/PDIF interface is used to transfer audio. The Ethernet network connector uses an RJ-45 socket. Phone line connector (RJ-11) is used to connect dial-up modems with phone lines. We can connect up to 127 devices using series of USB hubs. Colors for audio connectors are blue (line in), green (line out) and pink (microphone). DB-15 connector is often called VGA. VGA monitors are actually analog monitors. S-Video is used to connect our PC with TV. DVI connector is used to connect digital monitors to the PC. IEEE 1394, also known as the FireWire port, functions much in the same fashion as a USB.