My monitor won't change resolutions

Situation:

A MacOS PPC computer with a monitor that doesn't offer to change resolutions.

This can be 2 things especially:

A monitor adapter (DB-15 to VGA) for a VGA monitor relaying information incorrectly to the BeOS. The MacOS may work correctly although the BeOS doesn't.

The BeOS using the 'fixed frequency monitor' or 'stub' generic driver that doesn't support changing many of the screen preference options.

Things to try:

If you have an adapter, contact the adapter manufacturer and ask for BeOS compliant settings. Some reconfiguring can make these work if the adapter does correct hardware emulation. When it comes right down to it, Mac compatible monitors should do this, and adapters are a workaround.

If you have a Mac (DB-15) native monitor, the BeOS could be using the 'fixed frequency monitor' setting in the OS Chooser. Delete the MacOS file Boot:System Folder:Preferences:BeOS and then try the BeOS again. You can also boot the MacOS and make sure the 'fixed frequency monitor' setting is not checked.