On 8 Jul 2011, at 09:47, hvlems at zonnet.nl wrote: My Newstar 4 port KVM switch (PS/2) also shows weird behaviour. It works flawlessly with 4 pc's attached (regular Compaq branded pc's). With alpha's attached, especially a Multia an alphaserver 1000A or two or more as1200's then the mouse freezes after 15 to 20 minutes and a little later the keyboard gets into autorepeat mode. Attaching an external power supply to the Newstar didn't solve the problem. No idea what causes this behaviour. Simply, variations in how the KVM handles the signals. Most PS/2 KVMs have to 'dummy' the signal to the computer because PS/2 is not hot-pluggable on almost all systems. this means the signal has to be passed on from one device to the other and some KVMs do it better than others. Video is a worse issue. Some KVMs attempt to resync or retransmit video and it royally screws with the signal from some systems. -- Mark Benson My Blog: <http://markbenson.org/blog> Follow me on Twitter: http://twitter.com/mdbenson "Never send a human to do a machine's job..."