No Comments Written by Robert on July 23, 2008 – 3:50 pm

I was thinking about calling this section Ports Aplenty, which isn’t really a technical term, but nevertheless a pretty appropriate way to think about a laptop. Since the machine’s essentially a sealed box meant to travel the globe, clever designers have come up with all sorts of ways to allow you to attach external devices or communicate through wires, networks, pulses of light, or radio waves.

- RGB (monitor) port: This is an output of the same image seen on the LCD screen, converted to a signal that can display on a standard computer monitor or on a wall, using an external video projector.

- S-video port: This port sends a relatively high-resolution video output to modern TV sets that have a matching input. The picture quality is generally not quite as good as what you see on a computer monitor, but TVs are usually larger than monitors.

- USB port: This high-speed, highly adaptable port (some laptops offer two or even three of them) can be used for almost any type of device, from printers to external keyboards to various forms of add-on storage. A USB port provides both data and electrical power to attached devices, although some high-demand devices may require their own AC or battery power source. And if you need to plug in more devices than you have USB ports, you can add a hub that splits the signal and provides more connecting points.

- Ethernet port: This is the connection point between a network interface within the laptop and a wired network of other computers or devices. The connector, which looks like an oversized telephone jack, is technically called an RJ-45.

- Modem port: If the laptop has a built-in telephone modem, this port accepts a cable (with an RJ-11 connector) that attaches to the phone network.

- Headphone/speakers jack: The tiny connector can provide stereo audio to a set of headphones, send a signal to a set of external speakers, or connect to the sound circuitry of a television set, video projector, or stereo amplifier and speaker system. You can purchase adapters that allow just about any audio device to plug into and use the signal from this jack.

- Microphone jack: Attaching a microphone to this jack permits recording of voice or live music, or provides an input to speech-recognition software for dictation or verbal commands to the computer. The jack isn’t intended for use with amplified line signals, such as those that come from a stereo system or an iPod.

- Line-in jack: This connection, common only on laptops marketed as multimedia devices, allows connection of an external source of audio such as the output of a receiver, a VCR, or a stereo system. If your machine does not have a line-in jack and you want to record amplified sound, your best bet is to purchase a USB adapter that adds an external sound card and additional jacks.

- iLINK/FireWire port: You can call it iLINK or you can it FireWire or you can refer to it by its technical specification, IEEE 1394. Just call it fast. This is a competitive technology to the USB port that Sony (iLINK) has adopted for audiovisual devices including digital video cameras, by Apple (FireWire) for a broad range of devices, and by the 1394 Trade Association for anything and anyone.

- Specialized memory slot: Many modern laptops can directly read from tiny memory cards used in products including digital cameras, music players, PDAs, and cell phones. There is a dizzying array of these cards, including Memory Stick, Secure Digital, SmartMedia, xD Picture Cards, and CompactFlash. Toshiba offers a slot capable of working with all of the above, except CompactFlash, calling it a Bridge Media slot; other makers may call the same thing by other names.

- Infrared and WiFi ports: Technically, these aren’t ports since nothing plugs into them from the exterior of the laptop. Instead, these high-speed transceivers (transmitter/receiver devices) connect to similarly equipped devices, including standalone printers and keyboards to wireless networks that bring together other laptops, desktops, and Internet gateways.

What You See: Legacy I/O Options

The computer world is constantly changing, adding new technologies and improving on old ones. A bit of overlap is always there: The devices you used last week don’t suddenly become unusable this week just because a new and improved way of doing things has been introduced.

The industry even has coined terms to deal with this. If a new technology encompasses an older one without making it obsolete, that is called a downward compatible specification. As an example, USB 2.0, the current specification for that high-speed means of communication, is downwardly compatible with earlier USB 1.1 and 1.0 devices. The older equipment works just as it always did (at the slower original speed), while newer equipment designed for the newer specification performs faster and with new features.

The other term is legacy technologies. These devices and specifications have been made obsolete by new replacements; in most cases manufacturers continue offering support for these legacy devices for a few years, but eventually that ends. Examples of legacy devices include floppy disk drives, parallel ports, standard serial ports, and dedicated ports for external keyboards and mice.

My older laptops still have built-in floppy disk drives and individual mouse, serial, and parallel ports; my newer laptops dispense with both, advising users to attach old-style devices to the multipurpose USB port or to purchase a special cable that converts a USB signal to a parallel or standard serial connection. You may find these legacy ports on a laptop:

- Parallel port: Direct connection to older printers and certain other devices that require this sort of cabling in which 16 bits of information march along next to each other in separate wires instead of one behind each other in a serial connection. (Parallel used to be faster than serial, but modern technologies have reversed that trend.)

- Serial port: The original form of computer communication, used mostly for early telephone modems and some printers. Now completely replaced by USB circuitry; if your laptop does not offer this port and you need to emulate an older, slower form of communication, you can purchase a converter than uses the USB port.

- Keyboard/mouse port: The small, circular port used by desktop machines to connect keyboards and mice was also available on some older laptops.

There may have been one port for each device, or a single port able to work with either device. Why would you want an external mouse or keyboard when your laptop comes equipped with one of each already? First of all, an external device is usually larger and easier to use.

Secondly, you can choose to install a specialty pointing device or keyboard - a board with European accent characters, the slightly different arrangement of keys you find in some parts of the world, or a more precise trackball or optical mouse instead of the pressure-sensitive touchpad or stick used by most laptops. And finally, an external port allows you, in a pinch, to work around the failure of your laptop’s keyboard or pointing device.

- Docking station/expansion port: Older machines often were designed with a large connector at the rear that extended the computer’s internal bus to an external docking station on a desktop.

This was intended to allow addition of more ports, an external mouse or keyboard, external hard disk drives, and other devices. The docking station connector was usually a proprietary design that worked only with a particular manufacturer’s combination of laptop and expansion module. Docking stations were not much used by most laptop owners, and have been replaced by the multifunction USB port and by WiFi and wired networks.