WalkToFreedom
Posts: 9
Joined: Thu Oct 08, 2015 1:45 am

Translate Modeline to <hdmi_timings>

Wed Oct 28, 2015 11:26 am

Background: For an Aracade Cabinet project. Made a couple of posts in this thread viewtopic.php?f=100&t=86658&start=175 (pages 8 & 9) but thought it should really have its own thread.

I am trying to get the Pi to output 320x240p. I have had some success, via these settings:

Code: Select all

hdmi_group=1
hdmi_mode=8
But hdmi_mode=8 is actually 720x240p.

I know this modeline works fine for the CRT as I have had it running via an ArcadeVGA (dedicated PC video card):

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Modeline "[email protected],4Hz 15,7KHz (60Hz)" 6.460 321 336 368 412 240 242 245 264  -hsync -vsync

Modeline syntax: pclk hdisp hsyncstart hsyncend htotal vdisp vsyncstart vsyncend vtotal [flags] Flags (optional): +HSync, -HSync, +VSync, -VSync, Interlace, DoubleScan, CSync, +CSync, -CSync

eg: Modeline "1600x1200" 155   1600 1656 1776 2048   1200 1202 1205 1263
 #           (Label) (clk)     (x-resolution)        (y-resolution)
 #                     |
 #              (pixel clock in MHz)
Is it possible to translate the modeline to an <hdmi_timings>? This is what I came up with, but screen just stays blank? Is there any difference between CVT and DMT for custom modes, am I missing something else?

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hdmi_group=2
hdmi_mode=87
hdmi_timings=321 0 15 32 76 240 0 2 3 19 0 0 0 60 0 6460819 1

WalkToFreedom
Posts: 9
Joined: Thu Oct 08, 2015 1:45 am

Re: Translate Modeline to <hdmi_timings>

Mon Nov 16, 2015 8:50 am

I used these two pages to work out the correct timings but the timings still don't work

http://www.geocities.ws/podernixie/htpc ... .html#avga

http://www.epanorama.net/faq/vga2rgb/calc.html

#hdmi_timings=320 0 9 29 34 240 0 1 3 18 0 0 0 60 0 6162240 1

User avatar
rpdom
Posts: 15199
Joined: Sun May 06, 2012 5:17 am
Location: Chelmsford, Essex, UK

Re: Translate Modeline to <hdmi_timings>

Mon Nov 16, 2015 11:25 am

WalkToFreedom wrote:I used these two pages to work out the correct timings but the timings still don't work

http://www.geocities.ws/podernixie/htpc ... .html#avga

http://www.epanorama.net/faq/vga2rgb/calc.html

#hdmi_timings=320 0 9 29 34 240 0 1 3 18 0 0 0 60 0 6162240 1
I hope you removed the "#" from the start of that line before testing it? Otherwise it is just a comment and will have no effect.

WalkToFreedom
Posts: 9
Joined: Thu Oct 08, 2015 1:45 am

Re: Translate Modeline to <hdmi_timings>

Mon Nov 16, 2015 8:13 pm

Hi. Yes, I removed the comment ;-)

User avatar
rpdom
Posts: 15199
Joined: Sun May 06, 2012 5:17 am
Location: Chelmsford, Essex, UK

Re: Translate Modeline to <hdmi_timings>

Mon Nov 16, 2015 9:17 pm

rpdom wrote:...
Hmm, I thought I deleted that post after I noticed in another thread that you had removed the # :?:

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