BB XM Monitor Def for 1920x1200

I have the XM connected to a Samsung 245B but at the moment I’m limited to 1280×1024. Looking elsewhere I can see some limited support for 1920×1200 resolution on the BB XM using Linux. It’s only 34Hz in 24 bit colour but I would assume could get a better refresh rate in 256 colours as the memory overhead would be much lower.

The problem is I don’t understand the various parameters in !Makemodes enough to try and define such a mode – and all other attempts at using definitions from other monitors don’t seem to work.

Does anyone have any thoughts on this – is it even possible to drive 1920×1200 under RISC OS on the XM?

Thanks!

This is the highest resolution I can get on a Samsung 245B in 24bit colour. You’ll need a recent omap rom to cope with the higher pixel_rate.
The weird resolution is due to the 16:10 aspect ratio. 45Hz was the lowest the 245B would go.

# 1728 x 1080 (46Hz)
startmode
mode_name:1728 x 1080
x_res:1728
y_res:1080
pixel_rate:90500
h_timings:32,2,14,1728,0,2
v_timings:5,16,0,1080,0,0
sync_pol:0
endmode

Is there a 256 colour version at 1920×1200 or does the BPP not make any difference?

Just updated my ROM to the latest OMAP build and tried that Def and my particular 245B doesn’t like it so it’s probably a different revision.

Also I’m not sure the mode “test” thing in RISC OS is that great as I had to reboot to get the old mode back! In windows you just wait a bit and hit escape.

This was the highest res I could use on my HannsG:

# 1680×1050 (45Hz)
startmode
mode_name:1680×1050
x_res:1680
y_res:1050
pixel_rate:86000
h_timings:32,100,14,1680,0,98
v_timings:5,16,0,1050,0,0
sync_pol:0
endmode

• BENQ monitor on Beagleboard (for info – Alan, you’ve probably already seen this, and it’s unlikely to be any direct help anyway)
• Perhaps RPCEmu is worth looking at

Also I’m not sure the mode “test” thing in RISC OS is that great

Hasn’t it been recently updated for the ARMini (I think it’s this update in CVS)?

Any chance someone could knock together a MDF for me to use with RPCemu which has the rather odd resolution of 1438×798? Everything I’ve tried ends up with a corrupt display. Here’s one such hack…

# 1438 x 798 (40Hz)
startmode
mode_name:1438 x 798
x_res:1438
y_res:798
pixel_rate:86000
h_timings:32,284,0,1438,0,98
v_timings:5,13,0,798,0,3
sync_pol:3
endmode

1440×900 at 55hz is the most I seem to be able to manage with the 245B. Not really any bigger than 1280×1024 but at least it fills the screen.

Any chance someone could knock together a MDF for me to use with RPCemu which has the rather odd resolution of 1438×798? Everything I’ve tried ends up with a corrupt display. Here’s one such hack…

I don’t think you’ll have much luck with a width of 1438 – it isn’t divisible by four. I’m not sure what actual values RISC OS needs, or what a real VIDC needs, but anything less than 32bpp isn’t likely to work due to the start address of each line not being word aligned.

Good point. I had a feeling my odd numbers wouldn’t be helping. :) That cracked it, ta. I knocked it down to 1436 and it’s happy.

Just to say that we have at least one ARMini user running 1920×1200, so it is possible. However, you’d need to check the capabilities of the monitor before purchase. AFAIK samsungs can be pretty finickity about stuff. We’re likely to make our monitor stuff available as a separate purchase for xm users this summer, if people are interested. I believe the customer in question is running a HP screen.