Black Box KV2004A KVM Switchbox - ServSwitch Wizard DVI Dual Link (USB), 4 Port or 8 Port 4 x 1 4 x DVI I Video, 4 x Type B USB Rack mountable, Desktop

The ServSwitch Wizard™ DVI Dual-Link (USB) 4-Port or 8-Port has breakthrough USB True Emulation technology. This ensures that the full characteristics of the connected USB peripherals-including keyboards and mice-are passed to every system, so specialized features are quickly recognized on the attached devices. What's more, each computer retains this information, even if the device is plugged into another computer. Because of this technology, the switch avoids many of the limitations found in traditional emulations, enabling instantaneous switching and hotkey support.
You can switch up to four or eight PCs via hotkeys, mouse, or RS-232/V.24. The switch provides resolutions up to 2560 x 1600 or 2048 x 2048 at 60 Hz. Plus, it supports duallink DVI-D, single-link DVI-D, and VGA.
Intelligent options port
Flash upgrade the ServSwitch Wizard DVI Dual-Link (USB) via its intelligent options port. You can also switch it via simple RS-232 protocol or even dry contacts. When linked with another ServSwitch Wizard, the options port can be used for synchronous switching of multiple video heads.
USB 2.0 transparency
A clever architecture combines transparent USB 2.0 protocol with emulated keyboard and mouse control. To support this, there are two dedicated keyboard/mouse ports