Sometimes the screen become black for about 1, 2 seconds using MorphOS at 1920x1080 24bit.
I have this problem using MorphOS 2.x (from 2.x to 2.5)
Using also the game Fortis at very high res. (exemple at 1920x1080) I can see many times this problem (screen black for about 1, 2 seconds).
I use a Pegasos 2 G4@1000 rev. 2B5, SmartFirmware 1.2, AGP Ati Radeon 9250 256mb, monitor Samsung 2494HS. Same problem also with an other Pegasos 2 G4@1000 rev. 2B2, SmartFirmware 1.2, AGP Ati Radeon 9250 256mb, monitor Samsung 2494HS.
Well, it has nothing to do with Fortis, but your resolution in general. DVI is limited, to achive 1920x1080 on a single link dvi connection you have to have an option "reduced blanking" (this is afaik the way OS 4.1 does when you set the varaible +rb) As I don`t have a MorphOS Machine right now, I can`t have a look whether such an option exists. Another solution which might help is to reduce the refresh rate to something about 52 Hz. Best solution would be to have support for dual link, but afair none of the Gfx Cards supported by MorphOS offer dual link (Afair dual link starts with Radeon 9600)
sure It's not a Fortis problem :) (It was only an exemple)
Can you verify if there is an "reduced blanking" option in MorphOS 2.5 ?
In screenmode at 1920x1080 24bit I have: PIXEL CLOCK 138500100 Hz H Sync Lenght 336 V Sync Lenght 15 H Pulse Offset 48 V Pulse Offset 3 H Pulse Lenght 144 V Pulse Lenght 5 H Pole - V Pole + freq. H 61.3918 kHZ freq. V 56.0655 kHZ
I refered to Fortis because Digiman mentioned it explicitly, alas it is just a coincidence. Regarding "reduced blanking" I can`t confirm whether there is an option to enable it or not, however my Mac Mini should arrive in a few days and then I will have a look (A non-expert explanation of reduced blanking: A CRT`s ray has to be switched of after every line it "draws". TFT`s don`t have a line blanking intervall, thus blanking just eats bandwith. By reducing that blanking intervall, you gain more bandwith at no cost and you will be able to drive the max resolution of 1920x1200 for a single line dvi connection) And shouldn`t your vertical frequency been listed in HZ instead of kHZ? If so, afaik this is the value you may change (Another posibility to gain bandwith) but better have a look in you monitors datasheet (Value 52 instead of 56 HZ might work)
Puuh, Now I am a bit confused myself and hope I didn`t tell too much crap ;)
Sure its not fortris. Nobody ever thought that. It just somehow makes the problem worse. I only use 1280 * 1080. I will try to deduce the pixelclock. lets see what happens.
@Bladerunner thanks, if possibile give a look when you have time at this problem, I prefear an "option reduced blanking" then try to modify the settings layout screenmode.
@dIGIMAN If you find a solution, make me know, thanks :)
Now I am also a proud Owner of a Mac Mini and had a closer look into the Monitor Settings. However, as far as I can tell there indeed isn`t a reduced blanking option. (or it translates to something different in cgx language ;) )
So the only possible solution seems to be to reduce your frequency or use an analogue instead of a dvi cable, might help too (and yes I know it is actually somewhat stupid, but I guess it might be worth the try)