On Sat, Feb 15, 2014 at 7:51 PM, Ben Scott <dragonh...@gmail.com> wrote:
> 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 > Though the RasPi doesn't have VGA because of cost I've read. They wanted to make sure it worked on TV which meant HDMI and composite. So maybe the cost was HDMI/Composite vs HDMI/Composite/VGA don't know about. Plus, as you note, KVMs already had them; changing > creates a compatibility headache to no gain. > > That's what I think. > 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). > > I still see PS/2 on new systems. I wonder why they haven't disappeared from desktops and servers. They have on laptops. USB keyboards and mice & KVMs are much more common then VGA. > > 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. ;-) > Mine is 4 port, 1/2 the size of a mac mini. A bit shorter then a powered external DVD rom. > > -- Ben > _______________________________________________ > gnhlug-discuss mailing list > gnhlug-discuss@mail.gnhlug.org > http://mail.gnhlug.org/mailman/listinfo/gnhlug-discuss/ >
_______________________________________________ gnhlug-discuss mailing list gnhlug-discuss@mail.gnhlug.org http://mail.gnhlug.org/mailman/listinfo/gnhlug-discuss/
