monitor geometry/sleep/screaming on iMac?

[Administrator]

hi,

any way to make the usual monitor geometry adjustments (like the macos 
monitors panel) under linux?

(this is a blueberry imac)

also, the monitor screams, as in makes a high pitched noise at all 
times, which changes slightly when the display changes (such as squeaky 
noises during scrolling) any tips on how to change that?

also, how to get the display to sleep?  it would be great, because it's 
acting as a netatalk server, no need to have the monitor on 24/7.

thanks for pointers/tips