From Mark Thomas Mercado on Tue, 30 Jun 1998 in the
I've looked around on the web, and couldn't find any documentation on setting up X with two monitors (myhost:0 and myhost:1)... I would love to RTFM if anyone could point me in the right direction...
This would usually be called "multi-headed" mode and the different screens would be addressed as "myhost:0.0" and "myhost:0.1" -- "myhost:1.0" and "myhost:1.1" (etc) would refer to a different server or instance running on the same machine.
I don't know what this means on other forms of Unix --- but I think you'd usually see it on a system that was hosting multiple X Terminals via XDMCP. On my Linux boxes I usually see it as an extra instance of the X server running on a different virtual console (so my wife and I can each have a running copy on any of the systems around the house without having to disturb the other's).
In our case we run startx -- :1 to start the 2nd instance of our X server. We can then switch between them with the [Ctrl]+[Alt]+[Fx] sequence (or the [Alt]+[Fx] sequence to get to either of them from any of our text mode virtual consoles. (If you don't use a PC Unix that supports VC's this probably won't make any sense -- don't worry about it).
Getting back to multi-headed support:
This depends on your X server. Last I heard XFree86 servers (the suite of X servers that's most commonly used with Linux FreeBSD, NetBSD (PC) etc) don't currently support multi-headed operation.
I know that some of the commercial X servers for Linux (and presumably FreeBSD, etc) support it. Unfortunately I've never used a PC or Mac Unix that was configured this way. So, I don't know how it works. I've used an old Sun system set up this was --- but I didn't configure it or even look at it very closely --- it was just used for some compatability at a place where I was working, so I barely touched it.
I've used Macs that were multi-headed. That was a piece of cake to configure. I also noticed that Win '98 has this feature available --- so it might become much more common in the next year or so.
Anyway, check out the XFree86 FAQ at http://www.xfree86.org/ for more pointers.