DynaSync Technology Extends KVM Handshake to Monitors of all Resolutions – Part I

March 31st, 2011

KVM technology advancements don't exactly get consumers excited like an Apple product launch. In fact, the acronym K-V-M probably doesn't even register in most people's lexicon, even though they may be benefitting from the technology on a daily basis. But, while a KVM switch doesn't have the same cachè as a new tablet, our IOGEAR convergence geeks actually DO get excited when a new KVM product or development helps our customers. To remove the suspense for those wondering, KVM stands for Keyboard-Video monitor-Mouse . The products basically create a scenario where instead of needing one monitor, one keyboard and one mouse for every computer, a single set of these peripherals can be shared with a few or even thousands of computers in offices, businesses that use digital displays, data centers or even in the home on a smaller scale. A short history of KVM reveals that products in this category have been around since the early 1990s, when they were without an “M” and known as KV (Keyboard-Video monitor) switches. Integration of the mouse came in the mid-1990s when graphical operating systems with mouse-controlled user interfaces became popular and required mouse functionality. Like most connectivity solutions, KVM products are challenged to keep up with the rapid development of related technologies such as HD monitors, video electronics and the interconnections that tie them all together. This is where the patented DynaSync technology from ATEN International enters the equation. However, in order to understand DynaSync's A/V coolness factor and its relation to IOGEAR KVM/KVMP products, we must first explore how the related technologies and trends evolved to create serious demand. While KVM switches have been evolving for almost two decades, in recent years the nature of the monitor itself and of the video electronics in the computers have significantly changed. The “plain vanilla” VGA video outputs and the simple multi-sync monitors of way back in 1999 have given way almost exclusively to LCD monitors and a variety of video interconnect schemes that include VGA as well as its higher resolution derivatives such as QXGA, etc. Today we also find DDC (Display Data Channel) signals on VGA outputs, plus DVI (Digital Visual Interface) and HDMI (High-Definition Multimedia Interface) video, each of which incorporates different connectors, logical handshakes and video formats. Several aspects of this migration have made quick and easy switching between computers much more complicated. For one thing, LCD monitors typically have one “ideal” display resolution, unlike the older CRT video monitors. While a given LCD may be able to display alternate resolutions, these will not be as sharp as its optimum resolution. Consequently, the computers should, ideally, be set to drive the connected monitor at its optimum resolution. Fortunately, a data structure known as EDID (Extended Display Identification Data) exists that allows this automatic, optimized video setting to be obtained when a suitably equipped computer graphics card and monitor are directly connected to one another and the computer is booted up. EDID works because a ROM chip in the video display stores pertinent video data about that monitor in such a way that it can be “read” by a computer's graphics card. This process works quite well with a single video display and a single computer. For a fuller explanation of how EDID works, the all-knowing Wikipedia is a good source. Unfortunately for KVM switches, an increasing number of computers and digital peripherals are also equipped with HDCP (High-bandwidth Digital Content Protection). While HDCP is critical for discouraging unauthorized copying of protected programming material, the handshake between the display port of a computer/peripheral and the monitor may fail to occur when switching among HDCP-equipped computers. A KVM switch may be able to read a monitor's EDID and set the optimum resolution when booted up, but there's no mechanism in place to correct it when switching to other monitors. Users will generally end up with a non-native default resolution. This inconsistency can frustrate legitimate use of the system and makes the awesomeness that is EDID, moot. So what's a KVM switch to do? Stay Tuned for Part II



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IOGEAR enjoys long walks on the beach and romantic getaways. While not traveling, IOGEAR enjoys a great game of shuffle board whilst playing the banjo.