On Tue, Feb 4, 2014 at 1:17 PM, Tom Buskey <t...@buskey.name> wrote: > Why do servers still have VGA + PS/2?
From what I see, most have VGA and USB, these days. > Because most KVMs haven't switched? I'm not privy to their design meetings, but I would suppose: VGA is cheaper, both to build a video source, and to build a switch. DVI has higher connector costs, cable costs, and tighter signal tolerances than VGA (especially at lower resolutions). VGA only needs 5 conductors for a minimal implementation. DVI may also have mandatory and/or more complicated metadata signalling (vs VGA); that I don't know about. Plus, as you note, KVMs already had them; changing creates a compatibility headache to no gain. USB vs PS/2: USB connector is flatter (important in pizza box form factors), and cheaper, and more rugged. USB is hot-swappable, which means it's cheaper to build a switch -- you don't need to proxy the mouse, the way you do with PS/2. And you only need one channel from the switch to the computer(s), since the protocol supports multiplexing (hubs). > FWIW, I still have a KVM that will do serial mice. I used to, too, but it was bigger than most of the servers it would have been hooked up to. ;-) -- Ben _______________________________________________ gnhlug-discuss mailing list gnhlug-discuss@mail.gnhlug.org http://mail.gnhlug.org/mailman/listinfo/gnhlug-discuss/