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Software Support => GroovyMAME => Topic started by: bernieke on December 24, 2015, 06:07:32 am

Title: crt_emudriver + atom-15 = fully 15khz safe output?
Post by: bernieke on December 24, 2015, 06:07:32 am

If I modify my HD4870 bios with atom-15, and configure windows 7 to use crt_emudriver, will the graphics card then only output scart-safe signal through the whole boot process? Or will there still be a time during windows bootup where it could output 31khz?

Title: Re: crt_emudriver + atom-15 = fully 15khz safe output?
Post by: haynor666 on December 24, 2015, 10:18:28 am

Boards with UEFI can output 1024x768 for a while.

Title: Re: crt_emudriver + atom-15 = fully 15khz safe output?
Post by: Calamity on December 26, 2015, 10:22:19 am

Quote from: haynor666 on December 24, 2015, 10:18:28 am

Boards with UEFI can output 1024x768 for a while.

Not really, if you patch the bios with only the 15-khz option, all available modes will output 15khz. Because 1024x768 is impossible at 15 khz, this mode will be *disabled*, meaning that if the uefi bios is hardcoded to use it, it will simply output a black screen.

Title: Re: crt_emudriver + atom-15 = fully 15khz safe output?
Post by: Calamity on December 26, 2015, 10:27:02 am

Quote from: bernieke on December 24, 2015, 06:07:32 am

If I modify my HD4870 bios with atom-15, and configure windows 7 to use crt_emudriver, will the graphics card then only output scart-safe signal through the whole boot process? Or will there still be a time during windows bootup where it could output 31khz?

Yes, all the boot process will output a safe 15 khz signal, that's the purpose of the whole thing.

The risk is actually once you enter Windows and the default video driver is loaded. Because this driver bypasses the bios, it is still able to output whatever potentially dangerous signal. That's why my advice is to first setup the Windows side of things, CRT Emudriver, etc. Once you have a safe 15 khz Windows system, finish the video setup by flashing the bios.

Title: Re: crt_emudriver + atom-15 = fully 15khz safe output?
Post by: bernieke on December 26, 2015, 12:18:10 pm

Brilliant!

Thanks for the explanation!

Title: Re: crt_emudriver + atom-15 = fully 15khz safe output?
Post by: roccias on April 06, 2016, 06:59:38 am

Hy everyone and sorry for my English.

I resume this topic because I have a doubt. If i flash my Ati Radeon 4350 Hd with Atom and then I want come back to 31 khz  (for example for format my pc, install program,ecc) can we re-flash the bios or we have the risk to damage the card ? Basically we can flash and re-flash the bios of the card without problem?   Thank you

Title: Re: crt_emudriver + atom-15 = fully 15khz safe output?
Post by: Calamity on April 06, 2016, 07:27:02 am

Quote from: roccias on April 06, 2016, 06:59:38 am

Basically we can flash and re-flash the bios of the card without problem?   Thank you

Sure, no problem with that, just make sure to keep a copy of the original bios in a safe place.

Title: Re: crt_emudriver + atom-15 = fully 15khz safe output?
Post by: roccias on April 06, 2016, 07:30:03 am

Thank you very much calamity :notworthy: