Two Headed Penguins?

dmendesf asks: "The Octane2 workstation from SGI has a neat trick called PowerDuo that enables a single station to be driven by 2 keyboards, 2 mice and 2 monitors. Is it possible to do the same with Linux and USB mice, keyboards plus Dual Head videoboards?" How difficult would it be to develop an X11 solution to do this? Now take this a step further: could this be done with the secondary machine a network connection away?

Comments

I remember reading about this before...

[The guy standing ove]

I believe the following HOW-TO is what you're looking for is here

http://www.linuxplanet.com/linuxplanet/tutorials /3 100/1/

I've been thinking about doing the same thing myself. With a dual-processor machine, I'm sure I wouldn't notice a change in system performance.

clarification

[foobar104]

I see a lot of comments about X terminals and one about a dual-head graphics card.

That's not what the question-asker-person was talking about.

The Octane system that was referred to in the question is designed to support two users logged into the machine at the same time, each using a fully functional hardware graphics pipe. From the user's point of view, it's exactly like having your own Octane, complete with V12 ("really fast") graphics.

You can't do that with VNC or an X terminal, because those both involve running your application on the server and displaying its output over the LAN. That's not as fast as working on the local machine, and it doesn't provide you with hardware-accelerated graphics.

A dual-head output from your graphics card also wouldn't be enough, because to implement a system like this you'd have to have two graphics cards, one for each user.

SGI Onyx systems have supported this kind of thing for years; at one point it was marketed as a product called "GroupStation." The way they set it up wasn't particularly exotic, although it may depend on some features unique to the Xsgi X server. For instance, Xsgi has a "-pipe" option that tells it to manage the given graphics pipe; graphics pipes are numbered by the kernel at boot time, so on any multipipe machine you can refer to a specific pipe as 0, 1, 2, or whatever. I don't know if that option is unique to Xsgi or what.

Each user gets a mouse, keyboard, and monitor. The X server on the Onyx would be configured to run one instance of X on each graphics pipe, instead of one instance of X with a screen for each pipe. (In other words, :0.0 and :1.0 instead of :0.0 and :0.1.) Each X display gets an instance of xdm, so when you sit down you log in and go like you're the only user on the machine. You set up the bindings between mouse/keyboard devices and pipes in the Xservers config file, I think.

It should be possible, at least in theory, to do this with XFree86. I know multiple X sessions on one Linux machine are supported; I've done it myself with multiple XDMCP clients running at the same time. If XFree86 supports binding mouse and keyboard devices to X displays, then you should be ready to roll.

The only bad news is that you'd be limited to PCI graphics cards for your 2nd through nth heads, unless you have a motherboard with more than one AGP slot. None of the PCs at my office have more than one, so I'm not even sure whether such a beast exists.

So to sum up, I think this depends more on XFree86 than it does on Linux. If you want to try it, I'd start with the XFree86 documentation to find out if the features you'd require are supported.