Black Box Explains...Upgrading from VGA to DVI video.
Many new PCs no longer have traditional Cathode Ray Tube (CRT) computer monitors with a VGA interface. The latest high-end computers have Digital Flat Panels (DFPs) with a Digital Visual... more/see it nowInterface (DVI). Although most computers still have traditional monitors, the newer DFPs are coming on strong because flat-panel displays are not only slimmer and more attractive on the desktop, but they’re also capable of providing a much sharper, clearer image than a traditional CRT monitor.
The VGA interface was developed to support traditional CRT monitors. The DVI interface, on the other hand, is designed specifically for digital displays and supports the high resolution, the sharper image detail, and the brighter and truer colors achieved with DFPs.
Most flat-panel displays can be connected to a VGA interface, even though using this interface results in inferior video quality. VGA simply cant support the image quality offered by a high-end digital monitor. Sadly, because a VGA connection is possible, many computer users connect their DFPs to VGA and never experience the stunning clarity their flat-panel monitors can provide.
It’s important to remember that for your new DFP display to work at its best, it must be connected to a DVI video interface. You should upgrade the video card in your PC when you buy your new video monitor. Your KVM switches should also support DVI if you plan to use them with DFPs. collapse
Black Box Explains...Digital Visual Interface (DVI) connectors.
DVI (Digital Video Interface) is the standard digital interface for transmitting uncompressed high-definition, 1080p video between PCs and monitors and other computer equipment. Because DVI accommodates both analog and digital... more/see it nowinterfaces with a single connector, it is also compatible with the VGA interface. DVI differs from HDMI in that HDMI is more commonly found on HDTVs and consumer electronics.
The DVI standard is based on transition-minimized differential signaling (TMDS). There are two DVI formats: Single-Link and Dual-Link. Single-link cables use one TMDS-165 MHz transmitter and dual-link cables use two. The dual-link cables double the power of the transmission. A single-link cable can transmit a resolution ?of 1920 x 1200 vs. 2560 x 1600 for a dual-link cable.
There are several types of connectors: DVI-D, DVI-I, DVI-A, DFP, and EVC.
DVI-D (digital). This digital-only interface provides a high-quality image and fast transfer rates between a digital video source and monitors. It eliminates analog conversion and improves the display. It can be used when one or both connections are DVI-D.
DVI-I (integrated). This interface supports both digital and analog RGB connections. It can transmit either a digital-to-digital signal or an analog-to-analog signal. It can be used with adapters to enable connectivity to a VGA or DVI-I display or digital connectivity to a DVI-D display. If both connectors are DVI-I, you can use any DVI cable, but DVI-I is recommended.
DVI-A (analog) This interface is used to carry a DVI signal from a computer to an analog VGA device, such as a display. If one connection is DVI and the other is VGA HD15, you need a cable or adapter with both connectors.
DFP (Digital Flat Panel) was an early digital-only connector used on some displays.
EVC (also known as P&D, for Plug & Display), another older connector, handles digital and analog connections.
Black Box Explains...On-screen menus.
When the ServSwitch™ brand of KVM switches was first introduced, there were only two ways to switch: from front-panel push buttons or by sending command sequences from the keyboard. While... more/see it nowthis was more convenient than having a separate keyboard, monitor, and mouse for each CPU, the operator still had to remember key combinations and which server was connected to which port—leading to many cryptic, scribbled notes attached to the switch and to the workstation.
But with the advent of on-screen menus, an operator can use easy-to-read, pop-up menus to identify and select CPUs. It’s even possible to give each CPU a name that makes sense to you—names like “MIS Server,” “Accounting Server,” and so on.
Black Box Explains...CAT5: When more isnt always better.
In data communications applications, using products that exceed required capacities is usually not a problem. For example, if a 28.8K modem is required, a 33.6K or 56K model will work... more/see it nowjust fine.
But sometimes, more isnt better. Take KVM extenders designed to expect CAT5 and only CAT5 cable. Youd expect that Category 3 cable wouldnt be effective with these products, and you would be right.
But you may also assume that if Category 5 cable works fine, Category 5e, Category 6, and other higher-capacity cables would work even better. Unfortunately, this isnt the case, and heres why:
KVM extenders from many manufacturers, including ServSwitch CAT5 KVM Extenders, are designed specifically for the Category 5 specs defined by the TIA/EIA standard. Higher-level cables, such as Category 5e, have different characteristics and specifications. Although differences—specifically twist ratios—might seem small, they can have a negative impact on these extenders, which are expecting a true Category 5 transmission.
So with ServSwitch CAT5 KVM Extenders, you can think big with CAT5—just dont think bigger. collapse
Black Box Explains...Digital Visual Interface (DVI) and other digital display interfaces.
There are three main types of digital video interfaces: P&D, DFP, and DVI. P&D (Plug & Display, also known as EVC), the earliest of these technologies, supports both digital and... more/see it nowanalog RGB connections and is now used primarily on projectors. DFP (Digital Flat-Panel Port) was the first digital-only connector on displays and graphics cards; it’s being phased out.
There are different types of DVI connectors: DVI-D, DVI-I, DVI-A, DFP, and EVC.
DVI-D is a digital-only connector. DVI-I supports both digital and analog RGB connections. Some manufacturers are offering the DVI-I connector type on their products instead of separate analog and digital connectors. DVI-A is used to carry an analog DVI signal to a VGA device, such as a display. DFP, like DVI-D, was an early digital-only connector used on some displays; it’s being phased out. EVC (also known as P&D) is similar to DVI-I only it’s slightly larger in size. It also handles digital and analog connections, and it’s used primarily on projectors.
All these standards are based on transition-minimized differential signaling (TMDS). In a typical single-line digital signal, voltage is raised to a high level and decreased to a low level to create transitions that convey data. TMDS uses a pair of signal wires to minimize the number of transitions needed to transfer data. When one wire goes to a high-voltage state, the other goes to a low-voltage state. This balance increases the data-transfer rate and improves accuracy. collapse