Is possible to have dual monitors on haiku?

Hi is possible to have 2 monitors on the haiku beta ?.

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In my case, I tried to use a smart TV as external monitor so I plugged it in through HDMI. It didn’t work at all. Haiku didn’t detect any external monitor neither the smart TV detected the computer (this smart TV connected via HDMI was detected when I tried this under Linux). My computer has NVidia graphics, HDMI, Display Port and Thunderbolt ports, but not VGA.

I don’t know if Haiku can detect other monitors through other ports like VGA, Display Port or Thunderbolt, so if someone could tell us I’d like to know.

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As far as I know, multi-monitor is only supported by drivers for fairly old gfx cards. See this old thread.

I think I remember being able to use Haiku dual monitor running in a VM on newer hardware, where Haiku on the same baremetal didn’t support multi monitor. This could be a possible work around if a small drop in overall performance is acceptable. I have a quad core and 8gb ram, so this is rather painless for me. Ymmv. I also could be remembering wrong. It could have been running the Haiku vm instance in second monitor.

Haiku will support 2 mirror monitor at one resolution, so if you have 2 identical monitors you will get 2 identical displays, for the video cards that support this feature via defualt VESA. AFAIK none of the native drivers support dual head and or dual desktop or dual workspace useage. I think its more a lack of drivers support then any real holdback in the app server, workspaces woulc be how that should be leveraged. I am not sure how app server would handle drawing into 2 seperate and different resolutions or orientations though, say one monitor as a portrait and the other as landscape.

When i was using ZETA i remember theres was a tool that enabled dual monitors.
It will extend the desktop like it was a single monitor but double resolution, and use the 2 video outputs. I was using a geforce 7200 or something like that at the time.

We have support in drivers for old hardware (Matrox, non-hd Radeon, and possibly some others)
It works ok but app_server isn’t aware of it, so centering a window on screen ends up putting it between the tho monitors, for example.
None of the modern drivers haveecaught up with this yet. It would be great to have one of them working, so that we could easily work on the app_server side of things…

IIRC some work was done on the radeon driver to support the 2 heads, but not sure how far that got.

Radeon HD is caught up and awaiting multi-head management hooks from the app_server, we just need to implement the hooks at the app_server. I produced some early patches adding the groundwork to the API’s, but never got enough feedback to run with them.

The existing hacks used by the old radeon driver for multi-head are pretty bad.
This conversation always ends up at writing DRM wrappers and dropping our current drivers/accelerants, but then nobody ever wants to start that work (myself included).

I think @waddlesplash wants to work on DRM wrappers… not sure if that’s still the plan though.

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My main laptop has a Radeon HD apu. I also have another one that I just got that I’m repairing the busted screen. It’s a Radeon HD apu. I’ve done dual head in windows with one. They both have a vga port, and HDMI. What feedback could you use? Where would I start?

Is it even advisable to work on drm wrapping given the state of the AMD opengpu driver code and the vulkan API ? Seems like a lot of work, and what do we get AMD and Intel drivers, Intel hardware isn;t really powerful for ay real heavy compute or gaming, and the nvidia open driver is a train wreck. so unless someone plans to implements a wrapper allowing for linux drivers even closed ones to run on haiku, and those are buggy, is the juice worth the squeeze ?

I was able to get a duplicate video signal from the vga port on my laptop (core i3 350m , Intel hd graphics 1st Gen) on a monitor but it was very fuzzy…

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Couldn’t we get it working with the hack hooks and then rework app_server iteratively? At least we would have something?

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Hi, actually my drivers for nvidia and matrox both support dualhead. You’d best use dual head setup for that, though for the nvidia driver I added partly support for haiku’s native screenprefs app, which uses a trick invented by Thomas Kurschel for his original radeon driver.

Have a look here for details on my work:


I’m still amazing that such a basic feature as dual monitors is not support in the year 2020 !.
Windows 98 used to support up to 6 monitors more than 20 years ago.

Patches welcome!