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Software Support => GroovyMAME => Topic started by: Guilt on November 18, 2017, 06:30:05 pm

Title: HDMI overscan issue
Post by: Guilt on November 18, 2017, 06:30:05 pm
I hope this hasn't already been answered; I couldn't find it if so.

After installing CRT Emudriver on any of my compatible cards (currently Hd5450) and rebooting, any digital displays get a weird black border as if it were poorly compensating for overscan. Changing resolutions gives stranger results; some display at the wrong aspect ratio and some get more or less black bars. I was wondering if this was related to EDID detection?
It happens before and after use of VMMaker. I was able to get this working when I first built my machine a few months ago but now that I've swapped cards I'm faced with the problem again and can't figure out what I did.
Is this possibly a broken install? I also notice that on my 15khz display I'm unable to alter the horizontal timings of certain resolutions, notably 256x240.
Title: Re: HDMI overscan issue
Post by: buttersoft on November 19, 2017, 09:26:00 pm
Being unable to alter the timings sometimes happens to me as well. Often if you change desktop resolutions, and go again, it works. I can't seem to alter the 640x480@30i mode, myself, no matter what i do.
Title: Re: HDMI overscan issue
Post by: Guilt on November 22, 2017, 01:23:47 am
I've found that I can't resize the modeline I'm currently using for my desktop. I was able to readjust 640x480 by setting desktop to 320x240 temporarily. Just recently I took the timings from my adjusted 640x480 and pasted those over the NTSC definition in vmmaker's files and reinstalled modelines. Voila, near perfect overscan compensation for all resolutions.

Oddly enough while I was tinkering with this again yesterday I decided to open up setup.exe again and saw that I had the option to install the driver even though it was already displaying as "Radeon HD 5450 CRT Emudriver". Tried installing it for shits and giggles and surprise surprise my HDMI monitor's EDID is read properly and the underscan is gone. What a mystery.  :blah:
Title: Re: HDMI overscan issue
Post by: Guilt on November 25, 2017, 02:10:51 am
Good news everyone!

I ran into the issue again while switching to a better video card, and this time I found a solution! If anyone else ever runs into this problem, here's what you do:

Open the registry editor (win+r and type regedit)
Goto HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Video\
There will be many folders with long and confusing names. Open every single one of them.
You need to select each and every one of the subfolders called 0000. Create a DWORD in all of them named "DigitalHDTVDefaultUnderscan" and leave all those new keys at 0.
Reboot.

Tahdah! I have no idea whether you need to put a key in for every 0000 folder or not, but I'm so far experiencing no negative side effects of having done it this way.


Side note; never use the /setmax option of Nirsoft's MultiMonitorTool. It will permanently break your refresh rates and you will need to reinstall CRT Emudriver just to get your 15khz video to stop tearing,
Title: Re: HDMI overscan issue
Post by: haynor666 on November 26, 2017, 05:51:37 am
Since You are using 5450 I assume You are using windows 7 x64. I don't think there is need to use such tool because windows have already good enough menagement for multimonitors.