Dual screen laptop with 2 "Built-in" displays ?

[LifestreamVII]

Hi people !

I've managed to find and buy a pretty rare laptop recently: the Acer Iconia 6120 (a dual-screen laptop with no physical keyboard/touchpad, like a giant DS pretty much) and I've quickly tried to get macOS running on it. It has a 1st-gen Intel HD Graphics chip, also known as the Arrandale gen (more specs below). There's this well-known guide on insanelymac for modding the framebuffer kext for older versions of OS X up to High Sierra but I've seen people having success on installing Catalina (Big Sur too apparently) with Dosdude1's Catalina Patcher (which contains a Legacy Video Card patch that allows Arrandale integrated GPUs to work with QE/CI support).

So I took an unused HDD which had Catalina already installed on it (it's an old cloned partition from my main VAIO hackintosh) and applied the legacy GPU Post Install patch. Of course the OS booted with the EFI folder made for the Iconia, not the incompatible one that was on the EFI partition from the Vaio HDD. With the WEG patches on the config.plist file (framebuffer-patch-enable, etc.) the laptop booted almost successfully. I'm not sure if the hardware acceleration was fully working ? The dock had transparency and the UI animations were smooth but the Chess app was quite laggy.

Anyway, I was more interested in getting the two screens to work simultaneously, cause only the main (top) one showed something and the Settings panel showed only the Built-in display. The touch inputs were recognized on both screens though. I was thinking that full hardware acceleration might allow the second screen to be recognized (or by doing more patching on the GPU side). I booted into Windows to get more info about the screens and found out they're both connected through LVDS (according to Intel HD Control Center). Although, I later found here that apparently the second screen wasn't exactly identical to the main one (auo303c vs auo323c) and here that the AUO323C was an eDP interface
Either way, would it even be possible to enable both displays on macOS ? If so, does anyone have an idea where I should begin to look ? I've seen a few successful installations on the Zenbook Pro Duo (much more recent) but in this case the second display is connected via (internal) DisplayPort while the main one is LVDS, which makes things easier I guess ?

Might be worth to mention that I didn't do any DSDT nor EDID patching. I've looked into framebuffer patching and tried con1/con2 patches with LVDS type but I'm unsure about which Bus IDs I should pick.

Thanks in advance !

Specs :
CPU - Intel Core i5-480M
Graphics - Intel Graphics Media Accelerator (GMA) HD Graphics
RAM - 4GB
HDD - 620GB (1TB for the other one)
WiFi Card - BCM43225 (interesting )
3 USB Ports
HDMI, VGA
Model - Acer Iconia 6120

 

[EliteMacx86]

So I took an unused HDD which had Catalina already installed on it (it's an old cloned partition from my main VAIO hackintosh) and applied the legacy GPU Post Install patch. Of course the OS booted with the EFI folder made for the Iconia, not the incompatible one that was on the EFI partition from the Vaio HDD. With the WEG patches on the config.plist file (framebuffer-patch-enable, etc.) the laptop booted almost successfully. I'm not sure if the hardware acceleration was fully working ? The dock had transparency and the UI animations were smooth but the Chess app was quite laggy.

Most probably, the VRAM is available but not the full QE/CI.

Anyway, I was more interested in getting the two screens to work simultaneously, cause only the main (top) one showed something and the Settings panel showed only the Built-in display. The touch inputs were recognized on both screens though. I was thinking that full hardware acceleration might allow the second screen to be recognized (or by doing more patching on the GPU side). I booted into Windows to get more info about the screens and found out they're both connected through LVDS (according to Intel HD Control Center). Although, I later found here that apparently the second screen wasn't exactly identical to the main one (auo303c vs auo323c) and here that the AUO323C was an eDP interface
Either way, would it even be possible to enable both displays on macOS ? If so, does anyone have an idea where I should begin to look ? I've seen a few successful installations on the Zenbook Pro Duo (much more recent) but in this case the second display is connected via (internal) DisplayPort while the main one is LVDS, which makes things easier I guess ?

Yes, LVDS and DP are easy to patch, eDP ports are rare.

Might be worth to mention that I didn't do any DSDT nor EDID patching. I've looked into framebuffer patching and tried con1/con2 patches with LVDS type but I'm unsure about which Bus IDs I should pick.

There is a Framebuffer patching guide from Rehabman which might be useful for you.
I never had a Laptop with Arrandale so have no knowledge for fixing the acceleration. But people have got it working.

 

[LifestreamVII]

OK, thanks for your reply !
Right, I'm gonna look more into framebuffer patching. My main concern was if macOS prevented by default having two built-in displays connected simultaneously. Cause if I'm correct LVDS is associated to Built-in displays in the Displays section on the settings panel, so could they both appear at the same time despite this ? Also do you have an idea of which Bus IDs I could try for patching the second LVDS screen ? Obviously this combination is anything but common so most documentations only shows possible IDs for HDMI, DP, external interfaces. I tried Bus 0 on con1 then con2 (don't know yet which port for the second screen) but it didn't work, I guess because it's already taken by the main one.

One last question : in case the second display is an eDP connection, is LVDS considered the same as eDP for the con. type (02) in macOS ?

 

[EliteMacx86]

Right, I'm gonna look more into framebuffer patching.

Sounds good!

Cause if I'm correct LVDS is associated to Built-in displays in the Displays section on the settings panel, so could they both appear at the same time despite this ?

Yes, correct. Although, most of the time, the second display is routed via DP, in case of internal second display.

Also do you have an idea of which Bus IDs I could try for patching the second LVDS screen ? Obviously this combination is anything but common so most documentations only shows possible IDs for HDMI, DP, external interfaces. I tried Bus 0 on con1 then con2 (don't know yet which port for the second screen) but it didn't work, I guess because it's already taken by the main one.

The first option should be to define the framebuffer, then patch the Bus ID. Bus ID and connector types are two different things.

One last question : in case the second display is an eDP connection, is LVDS considered the same as eDP for the con. type (02) in macOS ?

Nah, both will be treated different via framebuffer connector patching.