h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

Nice overview, but a small yet important part is missing:

<quote> KVM switches can be either manual (with a rotary switch) or...

Yah right, but this only applies to the older, nearly obsolete AT-style computer mainboards that use a DIN 5-pin connector for the keyboard and a DB-9 serial connector for the mouse. The "rotary switch" KVM switches do not have the mouse/keyboard simulator circuit of the electronic ones...
Why bother?
Because all current PC's have so called PS/2 keyboard and mouse connectors (Mini-DIN 6 pin). Not only is it a different connector, it's a completely different interface, and unlike the older DIN/Serial combo the signals are neither buffered nor in any other way protected against transients and spikes. Go ahead, unplug the PS/2 mouse of your shiny new computer while switched on, then stick it back in. Repeat ten times. If you are lucky, the computer will simply crash. If less so, your mouse is toast. Maybe even your motherboard.
This is exactly what a mechanical (manual) KVM switch will do. So, don't get one for your server room. They ARE sold with PS/2 connectors (I've even seen older KVM switches "converted" to PS/2 with custom cables - ouch!), but these should be banned anyway. Even if they're way cheaper (I still have a feeling they are being subsidized by mouse manufacturers

I have seena PS/2 version of the manual type, and it too was junk

Althogh I am not knocking older technology, many new products offer convenience and reliability. USB, USB2, and Firewire(IEEE 1394) are "Hot Connect", and "Plug'n'Play". This allows you to disconnect one peripheral and connect another without shutting down and rebooting your computer. Also, many devices can be added ( Over 100 ) daisey-chain style and through "hubs". USB and Firewire switch boxes can be used without fear of crashes or damage.
Another comment. I have had "IBM compatables " and am now an APPLE convert.

Hurrah! (polishes the Apple logo on his computer)

I have used belkin switches and found them to be a problem like everyone. However, I came across blackbox model sw622, its excellent no freezing problem, hence would recommend it to anyone. see their site on www.blackbox.co.uk, and search for sw622. should you need a cheaper one, never used contact me on 07904353685

I prefer the Black Box switches as well, but Belkin are less than a third of the price.