2007 ATEN Technology, Inc. www.aten-usa.com
Why Network Administrators Should Explore the “V” in K-V-M Switches
-P03-
Adapter) and EGA (Extended Graphics Adapter) cards. These cards typically use DB-9 (9-pin D-con-
nector) outputs. These early digital video systems had very low resolution, limited color depth (not
many colors could be displayed), and signals could not travel more than about 10 or 15 feet without
visible degradation.
The Video Resolution Revolution – Modern Video Standards
Analog Video
Analog video signals eventually replaced the TTL digital format. Here, the video intensity is defi ned by
a continuously-variable voltage that typically ranges from zero to 700 millivolts (mV) DC per color. An-
alog-based video started out as VGA (Versatile Graphics Array), and then expanded to include SVGA
(Super VGA), and XGA (Extended Graphics Array) cards, among others. Analog cards typically use
HDB-15 (15- pin D-connector with 3 rows of pins) outputs. However, all 15 pins are not utilized for
signals with some systems using pins to convey coded information about the monitor back to the
video card. Analog video immediately increased the available resolution, color depth, and cable length
well beyond what early digital video could accommodate. Most VGA-capable monitors sold today will
work with almost any vintage VGAstandard video output card, though there are some caveats.
Analog – VGA Still Thrives
Much of today’s video remains analog. From the early 640 x 480 pixel ‘standard VGA’ resolution, VGA
style video cards and monitors capable of up to 2048 x 1536 pixels have emerged, and some cards
can drive multiple high-resolution monitors to create an even larger “virtual” screen image. Computer
monitors have also grown in screen real estate – the 1970s typical 12” diagonal display has today be-
come a 20”, 24” and even 30” monitor that is prevalent in some offi ces and data centers (not to men-
tion the projection systems). Simultaneously, color depth has increased with the maximum number of
colors displayed expanding from 16 or 256 colors up to millions.
CGA-EGA Video Connector (DB-9)
VGA Video Connector (HDB-15)
(23 Seiten)
Manymanuals.com
Manymanuals.de
Manymanuals.fr
Manymanuals.it
Manymanuals.pl
Manymanuals.cz
Manymanuals.es
Manymanuals-pt.com
Kommentare zu diesen Handbüchern