Datasheet

Most — but not all — external devices require a separate power source and are
generally used when the laptop is at a desk with an AC power supply.
In the list that follows, I’ve marked the ones that usually require independent
power with an asterisk. You can attach these devices to a laptop:
 Network: If you need to upgrade an old machine or work around a failure,
you can plug in the circuitry to exchange information with other comput-
ers or share devices, including a broadband modem for use of the Internet,
or a printer attached to any other computer that’s a member of the work-
group on the network. The common specification is called
Ethernet, and it
can use either a wired or a wireless (WiFi) connection to other devices.
 Printer
*
: A printer can be directly connected to a laptop using the USB
port. You shouldn’t have to carry your own printer around with you;
almost any USB printer can be attached and recognized by a current laptop
running Windows. Older laptops and printers may want to communicate
using a parallel port and connection; either the laptop or the printer can
use a converter cable that changes parallel data to serial information (or
the other way around).
 Broadband modem
*
: You can directly connect to a high-speed cable or
DSL modem to use the Internet. Most of these devices connect to a laptop
through an Ethernet or USB port.
 Scanner
*
: This useful device can import digital images of pictures or text;
that information can be kept as graphics, or the text can be put through
an
optical character recognition (OCR) software program to convert it to
editable data for use in a word processor. Scanners require a broad pipe to
convey a great deal of information; most current models use (you guessed
it, right?) a USB port. Some older scanners require a SCSI port, which isn’t
commonly offered on laptops, although once again some converters can
stand between the scanner and the . . . USB port.
 External hard drives
*
: You can easily add more storage with a plug-in
drive; external drives can be as small and light as a videotape and attach to
a USB or an eSATA port.
 External optical drive
*
: Plugging in an attached CD reader or burner, or a
DVD player or burner, is easier than installing a new one in your laptop.
Once again: You’ll make the connection through the USB or eSATA port.
 Digital still or video camera: Film? We don’t use no film around here no
more. Digital cameras have almost completely replaced film; in almost every
situation, they’re used in conjunction with a computer for storage, editing,
printing, and transmission of the pictures. Almost all current cameras
can output their files to a laptop using a cable to either the USB or the
iLink/FireWire port.
18 Part 1: The Laptop Computer
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