Hardware Autopsy
r & d BREAKING DOWN TECH —PRESENT AND FUTURE
60 MA XIMUMPC JUNE 2006
White Paper: DLNA Home Networks
JUNE 2006 MA XIMUMPC 61
want, and initiate a slide show with software
running on the PC.
According to the DLNA’s interoperability
standard, the end-user experience should
be seamless: Each device on the network
should not only recognize the presence of
every other device on the network, it should
also be able to identify its function and its
capabilities (via UPnP). Each of these devices
must then be able to communicate and
exchange meaningful information with each
other. Any DMP must be able to receive data
from any DMS. If the DMP is unable to play
the media in its native form, the DMS must
transcode the material on the fl y to a format
that the player is capable of playing.BRILLIANT! WHAT’S
THE CATCH?
The DLNA network is an attractive concept
with the potential to solve many of the
problems associated with integrating PCs
and consumer-electronics devices. It’s a
good fi rst step, but we see two signifi cant
fl aws with this initial implementation.
First, it seems the DLNA has decided to
punt on the issue of digital rights manage-
ment, at least for the time being. The consor-
tium’s stated position is that they recognize
the rights and expectations of both media
producers and media consumers, including
the concept of fair use. But that’s as far as
Version 1.0 of the DLNA’s Home Networked
Device Interoperability Guidelines go. In other
words, a device can earn its DLNA complian-
cy logo whether or not it’s capable of stream-
ing or playing DRM-encrypted media.
Second, the consortium needs to
expand the narrow universe of media
codecs that DLNA-certifi ed equipment
is required to handle. To earn its logo,
a device need only support two of each
type of the following image, audio, and
video fi le formats: JPEG, plus PNG, GIF, or
TIFF; LPCM (e.g., WAV fi les from an audio
CD), plus AAC, AC-3, ATRAC3plus, MP3,
or WMA9; and MPEG-2, plus MPEG-1,
MPEG-4, or WMV9. Each device can, of
course, support more than two of each
type of fi le format, but some scenarios—
say, MPEG-2 is the only video fi le format
the server and player have in common—
will choke today’s wireless networks.
Fortunately, the DLNA consortium
has all the right participants to resolve
these issues. With DLNA-certified prod-
ucts—including Buffalo’s LinkStation
Home Server and Denon’s AVR-4306
home-theater receiver—now trickling
onto the market, this space bears watch-
ing. Point your browser to http://www.dlna.org
for more information.Gaming Keyboard
Keyboards contain more moving parts than all the other components in your rig combined.
Most computer users—and this goes double for gamers—punish their keyboards with regu-
larity. To see what enables them to stand up to such beatings, we dismantled Logitech’s G15
gaming keyboard.Keyboard shell: The keyboard shell, and the keys them-
selves, are manufactured from injection-molded ABS plas-
tic, an incredibly tough but lightweight material.LCD: This four-inch wide, one-inch high LCD panel
offers 160x43 pixels of resolution. It’s capable of dis-
playing up to five lines of text with 26 characters per
line, and it can be programmed to display grayscale
images and animations (up to 30fps).Rubber mem-
brane: In the “old”
days, keyboards
had individual
springs beneath
each key. This
design delivered
marvelous tactile
feedback, but it
rendered the devices
relatively expensive
to manufacture.
Replacing the
springs with this
rubber membrane
enabled Logitech to
add new features,
such as the LCD,
without driving up
overall costs.Mylar sheets: There are actu-
ally three sheets of Mylar film in this
image. The bottom of the top sheet
and the top of the bottom sheet
are printed with a proprietary, silver-
based, conductive material in a pat-
tern that matches the key matrix. The
middle layer has holes in the same
pattern. When a key is pressed, the
two conductive layers are pushed
together to make a “switch” con-
nection that is then interpreted by
the keyboard controller. The rubber
membrane pushes the key back up.Keyboard controller:
This integrated circuit
interprets the signals
generated by the switch
connections that are
made when keys are
pressed.USB hub/LCD controller:
This integrated circuit is both
a two-port USB hub and a
controller for the LCD. The
keyboard draws a maximum
of 500mA from the host PC,
which limits the usefulness of
its two USB ports.Light pipe: The clear
plastic panel lying at the
bottom of the keyboard tray
is a light pipe. Light from a
series of LEDs is channeled
through it in order to back-
light the individual keys.
The white film beneath the
plastic ensures that the light
is evenly distributed.