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TICKET ARCHIVE -> MacBook Monitor Specs Needed

dsr - Feb 22, 2007 - 12:24 pm

To Whom It May Concern,

I am running FreeBSD 6.2 in Parallels Desktop on my MacBook 13", and I need to know the horizontal scan rate and vertical synchronization rate of the built-in monitor in order to configure Xorg. I searched Google and Usenet for Apple's display specifications but to no avail.

The FreeBSD Handbook says that those specs are needed for X11 to determine the proper resolution and, more importantly, the refresh rate. I don't want to burn out my monitor, so any help is greatly appreciated.

Thanks,
David

Yesurbius - Feb 22, 2007 - 7:40 pm

Hello David. Welcome to macosx.com! My name is Daniel and I'd be happy to assist you with this issue.

Nearly all modern displays will detect an incompatible sync rate, and avoid going to it. In the off chance that the display does not have a safety feature such as this, I can tell you from my own experience that you'll be fine, and won't damage your display unless you set it to some drastically out of range settings. Its safe to experiment within 10 hz. Start with a liberal setting, and just test 10hz at a time. I've been using XFree86 since 1995 - I've never blown or damaged a display.

I did find one thread however that I think will be of great use to you.

http://leaf.dragonflybsd.org/mailarc.../msg00220.html

It has the X config file settings that you need. These were obtained by another user just 'testing' settings.

Did you have any other questions?

dsr - Feb 24, 2007 - 11:28 am

Hi Daniel,

First of all, thank you very much for your help. While that link appears to be specific to the MacBook Pro's monitor (same aspect ratio but greater resolution than 1280x800, perhaps?), I took your advice not to worry about damaging the monitor, and I experimented with different settings. Thanks to your link, I Googled 1280x800 horizsync vertrefresh macbook and found that 28-64 for HorizSync and 43-60 for VertRefresh seemed best for the 13" MacBook.

A new problem, however, has arisen. Even with the proper xorg.conf settings, the X server's display area seems considerably larger than my screen size (i.e. the tops of the xterm windows aren't visible and neither is the xclock on the right). This occurs when Parallels Desktop is in full screen. In normal mode, I can see the whole screen (but not at one time) by dragging the Parallels window around in Mac OS X. This problem persisted when I temporarily removed the HorizSync and VertRefresh lines from my xorg.conf file. I don't know if this is a problem with Parallels Desktop or not, but I hope you can help!

Thanks,
David

Yesurbius - Feb 24, 2007 - 12:48 pm

I have never used paralells, so I can't be sure on its effects in regards to the display.

It is normal for X to be slightly offset since we have to manually put the settings in - whereas in Windows, the driver handles it. What you are looking for is a program called xvidtune (you may already have it). It adjusts the zoom, pan, scroll on your display, and gives you the option to show the appropriate mode line that you can put into your X config file.


I hope that helps. Was there anything else I can assist you with?

Yesurbius - Feb 24, 2007 - 12:56 pm

I did some more reading, and it seems that due to the nature of the 915 chipset on the Macbook, X is unable to display a true 1280x800 resolution. They have made a program which implements a bios hack.

Its called 915Resolution - here is the homepage: http://www.geocities.com/stomljen/ - be sure that others have tried it on your model of macbook before trying it however - you wouldn't want to damage anything.

Once again, I hope this helps.

dsr - Feb 24, 2007 - 2:28 pm

Hi Daniel,

I have used 915Resolution with various Linux distributions (successfully), but I did not think to use it with FreeBSD. It works well on Linux, so I am optimistic. Thanks for the suggestion and for your time over the last couple days.

Regards,
David

Yesurbius - Feb 24, 2007 - 2:46 pm

Your welcome. Please let me know if there is anything else I can do for you.

dsr - Feb 24, 2007 - 5:51 pm

Unfortunately, it looks like Parallels Desktop does not virtualize the MacBook's Intel GMA 950, so 915resolution does not apply. I will research this further, but I have nothing left to ask of you. Thank you for helping me with the HorizSync and VertRefresh settings.

Yesurbius - Feb 24, 2007 - 9:16 pm

You are very welcome. Thanks for using macosx.com!

dsr - Feb 26, 2007 - 9:52 am

Just to let you know, the problem is resolved. It turns out that I needed to add the following line (or a similar Modeline) to the Monitor section of my xorg.conf file instead of the HorizSync and VertRefresh lines:

Modeline "1280x800" 83.91 1280 1312 1624 1656 800 816 824 841

Now the resolution is correct. Thanks again for all your help and take care.