Mac OS 9 Discussion > Mac OS 9, Hacks & Upgrades

G4 MDD ATI128 Pro

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msw:
I have this video card, and unfortunately it has a ADC connector on it instead of regular dvi.  It does have a vga port that seems to work when plugged into a VGA monitor as long as the refresh rate is something it can handle.  When I use low resolutions, even 640x480, 800x600, 1024x768, 1280x1024 they all show on the vga monitor.  At this point, I can hot swap the vga monitor with a VGA to hdmi adapter and everything works.  If I reboot, the first few minutes work at that resolution without any trouble.  The moment it switches to the desktop it blanks out.  I'm guessing some late running extension switches the VGA port somewhere outside of the range of the adapter.  If I plug the vga monitor back in, it's blank.  It seems that it somehow may sense the difference and behave differently.  I would be satisfied if I set the resolution and it did not try to do anything magic when the desktop loads.  Any ideas?  Any extension I could disable to prevent this?  I might lose some performance on the ATI card for acceleration or something, but I just want pull up and play games that pre date that.  Thanks in advance.  I am sorry if there is a post somewhere that I missed that prescribed a fix already.

IIO:
when MacOS boot process switches to the desktop/finder, usually the resolution is changed once more.

so there is a chance that you see what you see because it tries to switch to a certain resolution which is not supprted by your setup.

you could try to 1.) boot with extensions off (hold shift at startup), 2.) boot from a CD (hold c) or any other alternative OS9 install (hold alt), or 3.) if you have OSX on this machine, go and delete the OS9 monitor prefs.

there are probably more approaches.

msw:
Thank you for your very quick response!  I tried to zap pram, remove files.  Some success, but always ending in failure for me.  Ultimately, I just bought a card that had DVI directly on it, zapped the pram and so far so good (a couple of hours ;)  I don't get all the available resolutions that VGA had, but it seems to know which ones it can use that actually work.  Now I have a somewhat newer machine to run a lot of legacy software from my prior mac days!

The ISO builds for OS 9 are wonderful to allow this community to continue and I thank all the contributors!

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