[Solved] OS 10.11.6 Host to OS 10.6.8 display resolution issue

[Virtual Charles]

Hello,

I've installed VBox 5.1.28 on my El Capitan Mac and want to run 10.8.6 (Snow Leopard) as a guest OS so I can use applications that require Rosetta. It has gone well as far as it goes. I can log in, run applications etc. but I cannot change the guest OS's screen resolution. It is stuck at 1024x768. Hard to believe there was a time when that was high resolution.

I've used VBox under Linux and Windows for many years, installing both as guest OSs numerous times. There's always some sort of "Guest Additions" CD to install, but there doesn't seem to be such a thing for Mac OS. What is the proper way to get higher than this fixed 1024x768 resolution?

Interestingly, it turns out "seamless mode" is not supported either. Maybe this is connected?

By the way, I have installed the Oracle VM VirtualBox Extensions Pack.

Thanks for any and all help. Not sure what else I could tell you, but let me know if you need more info.

Best,

Charles Wright

[socratis]

Aren't you in luck Charles
First a couple of background. You cannot resize an OSX guest, or run it in seamless mode because of the lack of Guest Additions for OSX (among other guests). On top of that, OSX does not allow you to set arbitrarily the screen resolution (like Haiku for example), it takes its value from the EFI boot code. It's fixed, like on a real OSX system (except the retina ones).

The (up to) 5.1.x VirtualBox series contained a fixed list of EFI resolutions. I can't point you to the online manual anymore (it covers 5.2.0 at the moment), but if you have 5.1.28 installed go to Help » Contents » Ch. 3.13.1 Video modes in EFI. The available resolutions were 640x480, 800x600, 1024x768, 1280x1024, 1440x900 and 1920x1200.

The newly released 5.2.0 VirtualBox however adds custom resolutions for EFI. A lot of them actually. If you take a look at the same Video modes in EFI chapter, either the online version, or the PDF if you update to 5.2.0, you'll see a whole lot more available resolutions:

Code: Select all

VGA        640 x  480, 32bpp, 4:3
SVGA       800 x  600, 32bpp, 4:3
XGA       1024 x  768, 32bpp, 4:3
XGA+      1152 x  864, 32bpp, 4:3
HD        1280 x  720, 32bpp, 16:9
WXGA      1280 x  800, 32bpp, 16:10
SXGA      1280 x 1024, 32bpp, 5:4
SXGA+     1400 x 1050, 32bpp, 4:3
WXGA+     1440 x  900, 32bpp, 16:10
HD+       1600 x  900, 32bpp, 16:9
UXGA      1600 x 1200, 32bpp, 4:3
WSXGA+    1680 x 1050, 32bpp, 16:10
Full HD   1920 x 1080, 32bpp, 16:9
WUXGA     1920 x 1200, 32bpp, 16:10
DCI 2K    2048 x 1080, 32bpp, 19:10
Full HD+  2160 x 1440, 32bpp, 3:2
Unnamed   2304 x 1440, 32bpp, 16:10
QHD       2560 x 1440, 32bpp, 16:9
WQXGA     2560 x 1600, 32bpp, 16:10
QWXGA+    2880 x 1800, 32bpp, 16:10
QHD+      3200 x 1800, 32bpp, 16:9
WQSXGA    3200 x 2048, 32bpp, 16:10
4K UHD    3840 x 2160, 32bpp, 16:9
WQUXGA    3840 x 2400, 32bpp, 16:10
DCI 4K    4096 x 2160, 32bpp, 19:10
HXGA      4096 x 3072, 32bpp, 4:3
UHD+      5120 x 2880, 32bpp, 16:9
WHXGA     5120 x 3200, 32bpp, 16:10
WHSXGA    6400 x 4096, 32bpp, 16:10
HUXGA     6400 x 4800, 32bpp, 4:3
8K UHD2   7680 x 4320, 32bpp, 16:9

You can issue the command:

• VBoxManage setextradata "<VMname>" VBoxInternal2/EfiGraphicsResolution HxV

where you get your "H" and "V" values from the list above. If you enter a different value from the available ones, it will drop down to the closest lower resolution.

If you're not happy with any of the above, you can additionally issue a Custom Mode command (you can have up to 16 of them):

• VBoxManage setextradata <"VMname"> "CustomVideoMode1" "1234x978x16"

[Virtual Charles]

Ah yes! I am indeed in luck.

Believe it or not, this is the first time I've actually had to crack open the online manual. Anyway, I've achieved the desired screen resolution.

Thanks!

Charles

[socratis]

I've achieved the desired screen resolution.

Great, thanks for the feedback. Marking as [Solved].