800x480 on intel 945GM/GMA950 - is it possible?

**Giuliano** · 04-17-2007, 08:11 AM

800x480 is the native resolution of the LCD, and things generally look best at their native resolution.

And 800x480 is actually 15:9.

If you go with a non-native resolution, the VGA controller board will have to scale it down to 800x480 or thereabouts, so you'll lose image quality.

Also, anyone who wants to try Vista let me know.. I think I got those timings down too.

**BadCyborg** · 04-17-2007, 12:39 PM

@hithere: actually the correct size for 1280 for most widescreen monitors should be 1280x800, a mode that is found on Linux and OS X, but somehow converted into the oddball rez of 1280x768 (and with the advent of HD video, 1280x720 too) by Intel. Neither is far from being the correct aspect ratio. And in the case of mini-sized PCs, the output is from VGA (the only port on GMA) instead of DVI, there isn't any proper hardware scaling to add black bars on top and bottom of your screen. How do we know 1280x720 isn't the right aspect ratio? We draw a circle on the screen and measure.

To get 1:1, let's do a simple calculation. My monitor comes with the native rez of 1680x1050, so the aspect ratio is 1.6. 1280 divided by 1.6 is precisely 800. 1024 divided by 1.6 is 640. And so on. All the resolutions I stated above come from Linux and OS X.

Giuliano, I'd be more than happy to furnish you with the other details. Anything to eradicate this Intel mistake. What do I need to find those info?

**rigg419** · 04-17-2007, 12:57 PM

Sorry, a bit off topic and unrelated to car pc's.

First, I gotta give props to Giuliano. Whenever you put out something like this which is a total solution to a common problem, you're going to get morons like me asking stupid questions. that said....

I have an old (2005 is old in computer terms lol) alienware sentia with an intel chip. I use it as an HTPC and have it plugged into my 720p TV (Samsung HL-S5686W DLP if that helps), but the sentia won't output 1280 x 720, only 1024 x 768 (which looks odd) and 1280 x 800 (which the tv won't display).

The version of powerstrip I own (bought it a while back for my last carpc) is laughed at by the intel driver, and so I was wondering if there's a way I can make/find a driver for my chipset -Intel 82852/82855 (855GME)- which will allow the sentia to output 1280 x720 @ 32bit color and 60hz?

Thanks, and sorry for the unrelated/stupid question, but it's been a thorn in my side since I got the tv in february.

**Giuliano** · 04-17-2007, 01:07 PM

Probably, yes.

The Intel graphics have some serious flexability built in, especially for an onboard graphics chip.

I'll look at it tonight.

**rigg419** · 04-17-2007, 01:22 PM

Thanks Giuliano, I really appreciate it.

**BadCyborg** · 04-17-2007, 01:48 PM

Giuliano, do you think this might get you what you need? Thanks again.

**Giuliano** · 04-17-2007, 05:15 PM

BadCyborg:

Yeah, the Phoenix EDID editor is useful sometimes.

Run it on your machine, and then click the Extract EDID Registry button:

The timing parameters we want should be shown here..

**Giuliano** · 04-17-2007, 06:19 PM

Originally Posted by rigg419

Sorry, a bit off topic and unrelated to car pc's.

First, I gotta give props to Giuliano. Whenever you put out something like this which is a total solution to a common problem, you're going to get morons like me asking stupid questions. that said....

I have an old (2005 is old in computer terms lol) alienware sentia with an intel chip. I use it as an HTPC and have it plugged into my 720p TV (Samsung HL-S5686W DLP if that helps), but the sentia won't output 1280 x 720, only 1024 x 768 (which looks odd) and 1280 x 800 (which the tv won't display).

The version of powerstrip I own (bought it a while back for my last carpc) is laughed at by the intel driver, and so I was wondering if there's a way I can make/find a driver for my chipset -Intel 82852/82855 (855GME)- which will allow the sentia to output 1280 x720 @ 32bit color and 60hz?

Thanks, and sorry for the unrelated/stupid question, but it's been a thorn in my side since I got the tv in february.

rigg419,

Here's your driver package for 1280x720 (progressive) 32-bit @ 60hz:

http://moschini.org/855GME-1280x720p.zip

File size is 925k as before.

Extract, go into the Utilities folder, and run Setup.

This should spit out 1280x720 non-interlaced on the analog VGA port as the only adapter.

If you have DVI instead, let me know..

**Giuliano** · 04-17-2007, 06:28 PM

This is also good info:

http://isnwiki.jot.com/WikiHome/Articles/111111431

There's a section in the .inf files for the Intel Video drivers for the 915, 945, and 965 chipsets that allows you to use custom EDID timings right from the INF.

For example, this is one that I made for 800 x 480 (Xenarc timing) using the Vista drivers:

Code:

[NonEDIDMode_AddSwSettings]
HKR,, TotalDTDCount, %REG_DWORD%, 1  	; This shows number of DTDs to be used. ;  0-->Disable the feature.
;Following keys have 20 bytes (18 byte DTD + 2 Byte flags).
HKR,, DTD_1,%REG_BINARY%, 96, 96, 20, e8, 30, e0, e8, 10, 28, 50, 00, 00, 19, 10, 00, 00, 00, 00, 00, 00	;800 x 480
HKR,, DTD_2,%REG_BINARY%, 01,1D,80,18,71,1C,16,20,58,2C,1A,00,00,00,00,00,00,86,37,01		;1920x1080@60...Interlaced
HKR,, DTD_3, %REG_BINARY%, 01,1D,80,D0,72,1C,16,20,10,2C,1A,80,00,00,00,00,00,86,37, 01		;1920x1080@50...Interlaced
HKR,, DTD_4,%REG_BINARY%, 01,1D,00,BC,52,D0,1E,20,B8,28,25,40,00,00,00,00,00,04,37, 01		;1280x720@50....Non-interlaced
HKR,, DTD_5, %REG_BINARY%, 01,1D,00,72,51,D0,1E,20,6E,28,25,00,00,00,00,00,00,06,37,01		;1280x720@60....Non-interlaced	
HKR,, DTD_6,%REG_BINARY%, 00, 00, 00 ,00, 00, 00,00, 00, 00,00, 00, 00,00, 00, 00,00, 00, 00,00, 00	;Fifth DTD

That 5th line is actually where I pulled the 1280x720 @ 60 hz timings for rigg419.. I had to decode it for the individual parameters to plug into a DTD for the IEGD driver tool.

It's a serious mind twister to decode, though.

Here's the key:

Code:

These are VESA standard timings information in EDID.  The decoder ring for the 18 bytes is as follows:  
   
   1. Low Byte of DClk in 10 KHz
   2. High Byte of DClk in 10 KHz
   3. Horizontal Active in pixels, LSB
   4. Horizontal Blanking in pixels, LSB
   5   Bit 7-4: Upper 4 bits of Hor. Active
   5   Bit 3-0: Upper 4 bits of Hor. Blanking
   6.  Vertical Active in lines, LSB
   7.  Vertical Blanking in lines, LSB
   8   Bit 7-4: Upper 4 bits of Vert. Active
   8   Bit 3-0: Upper 4 bits of Vert. Blanking
   9. HSync Offset from Hor. Blanking in pix., LSB
   10. HSync Pulse Width in pixels, LSB
   11  Bit 7-4: Lower 4 bits of VSync Offset
   11  Bit 3-0: Lower 4 bits of VSync Pulse Width
   12  Bit 7-6: Upper 2 bits of HSync Offset
   12  Bit 5-4: Upper 2 bits of HSync Pulse Width
   12  Bit 3-2: Upper 2 bits of VSync Offset
   12  Bit 1-0: Upper 2 bits of VSync Pulse Width
   13. Horizontal Image Size, LSB
   14. Vertical Image Size, LSB
   15  Bit 7-4: Upper 4 bits of Hor. Image Size
   15  Bit 3-0: Upper 4 bits of Vert. Image Size
   16. Horizontal Border in pixels
   17. Vertical Border in lines
   18. Flags:
      Bit 7:   0 = Non-interlaced, 1 = Interlaced
      Bit 6-5: 00 = Reserved
      Bit 4-3: 11 = Digital Separate
      Bit 2:   Vertical Polarity (0 = Negative, 1 = Positive)
      Bit 1:   Horizontal Polarity (0 = Negative, 1 = Positive)
      Bit 0:   0 = Reserved" 
   19. Leave as 37
   20. Leave as 21

**rigg419** · 04-17-2007, 07:17 PM

Originally Posted by Giuliano

rigg419,

Here's your driver package for 1280x720 (progressive) 32-bit @ 60hz:

http://moschini.org/855GME-1280x720p.zip

File size is 925k as before.

Extract, go into the Utilities folder, and run Setup.

This should spit out 1280x720 non-interlaced on the analog VGA port as the only adapter.

If you have DVI instead, let me know..

I do in fact use VGA, you must be a mind reader!

I can't wait to get home so I can try this. Do you have a paypal? I'd love to throw you a quid as a token of my thanks. Alternatively, I'm a decent graphic designer if you need something photoshopped