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Rose Electronics Bliss KVM Switch

  • Editors' rating
    8.0 Excellent


  • Quick and easy to use
  • good price
  • Mac compatibility


  • Cable could be longer

So you have a pair of computers around your desk, both of which you want to control but you don't want the expense and loss of desk space that a pair of monitors will entail. Maybe one of them is a Linux server and the other a desktop -- or one could be a Mac. What you need is a KVM (Keyboard, Video, Mouse) switch that will allow each computer to believe that it is exclusively connected to the three devices that make up the user interface hardware, while allowing you to switch at will between them. Rose Electronics, a long-term player in this market and which claims to have invented the KVM switch, offers what is the lowest-cost solution that we've seen so far.

The £32.99 (ex. VAT) Bliss KVM Switch consists of a small console connection with an analogue VGA connector and two PS/2 ports, into which you connect your monitor, keyboard and mouse respectively. Attached to this unit are two tri-headed computer cables, one two metres long, and the other one metre long. On our version (model UKBL-2PU), one cable was terminated with one VGA and two PS/2 connectors for the first computer's monitor, keyboard and mouse sockets, while the second cable replaced the PS/2 ports with USB. You can also get a PS/2-only version.

Plug it all in, switch on, and a pair of LEDs on the console connection tells you which computer is on, and which one you're connected to. You alternate control between the two computers using special key combinations that are unlikely to conflict with others you may use -- left-Ctrl-1 and left-Ctrl-2, for example. The instructions show alternatives for Mac users.

The only big issue for KVM switches is the video resolution limit. It's a matter of frequency: the higher the resolution and refresh rate, the more likely the cable is to degrade the signal.

Rose rates the system for resolutions up to 1,920 by 1,440 at 65Hz, or a bandwidth of 180MHz. This means that, if you increase the refresh rate to 75Hz, you'll still be within limits even on a wide-screen display at 1,920 by 1,200. On a more standard display of 1,600 by 1,200, a refresh rate of 90Hz will still keep you within bounds.

We had no problems with the system, and can recommend it as a tightly focused solution for a particular situation.