My 1st gen Mac Pro with a custom graphics card (ATI Radeon) does not show any boot prompt. Actually it doesn't show anything until Aqua comes up. I need boot prompts and pre-GUI screens for multiple OSs.
Also when I hit alt during startup screen stays black.
Verbose Boot is on.
Is there any way to put that thing in always-on mode?
Best Answer
"Custom graphics card" is the problem… or more precisely, PC graphics card, not Mac.
Unless you bought one that was already Mac-flashed you will get nothing until the OS starts up.
The only two options are
More info/opinion that I can reasonably précis in here - http://forums.macrumors.com/threads/the-golden-guide-to-flashing-graphic-cards.877441/
Actually, from that I notice that the Zeus flashing tool is by Oskar Groth, aka Cindori - which ought to make it at least a trustable method
See - https://www.cindori.org/software/