Problems with SwitchRes??

[Chainsaw]

Hello. A while back I posted here relating to R-Type, and got some excellent support. I hope you can help me again 

I've only been able to turn my cab on today; I've stripped it down and am now racing to get it ready for the family for Xmas. It's a Sega Naomi with a MS-2932 CRT, which is 640x480 31khz.

I'm running mame from the command line for tests, but ultimately I'm using HyperSpin so I've limited total modes in vmmaker to 95.

My issue seems to be that SwitchRes isn't using the correct resolution; or possibly the correct resolutions don't exist. I'm not sure. I'm probably doing something daft 

In the next attachment I'll show the game logs (this first post will contain other info I think may be required) but basically, with the exception of R-Type, every game I tried tonight looked to be choosing the wrong resolution and / or frequency. At least that's what I think was happening.

As R-Type worked, I tried forcing the resolutions for these other games as well, but I had the same result.

Any advice is greatly appreciated. Thank you,

Matt

[Chainsaw]

There are the log files. Other than R-Type, which I'm including as an example, all these other games (these were the only ones I tried) seems to select an incorrect resolution and / or frequency.

[haynor666]

I'll suggest to stop listing resolution from XML and make custom ResList.txt file with only resolution that you need. IS this a tri sync monitor ? Are you rotating your monitor (in VMMmaker.ini looks like you not)?

[Calamity]

My issue seems to be that SwitchRes isn't using the correct resolution; or possibly the correct resolutions don't exist. I'm not sure. I'm probably doing something daft 

Switchres is working fine as far as I see. The resolutions are the expected ones provided you're in a 31 kHz setup. The wrong refresh rates are from vertical games which use 512 lines (256 x 2, or 512). You simply can't get 512p@60 Hz at 31.5 kHz.

So either increase the horizontal frequency:

monitor custom
crt_range0 31400.00-31500.00,49.50-65.00,0.940,3.770,1.890,0.349,0.064,1.017,0,0,400,512,0,0

(The remarked value is the default for arcade_31. Raise that value at your own risk)

Or, tell Switchres not use 512p:

monitor custom
crt_range0 31400.00-31500.00,49.50-65.00,0.940,3.770,1.890,0.349,0.064,1.017,0,0,400,480,0,0

(if you put that in the vertical.ini file it will work and still don't affect Irem games, MK, etc.)

[Chainsaw]

My issue seems to be that SwitchRes isn't using the correct resolution; or possibly the correct resolutions don't exist. I'm not sure. I'm probably doing something daft 

Switchres is working fine as far as I see. The resolutions are the expected ones provided you're in a 31 kHz setup. The wrong refresh rates are from vertical games which use 512 lines (256 x 2, or 512). You simply can't get 512p@60 Hz at 31.5 kHz.

So either increase the horizontal frequency:

monitor custom
crt_range0 31400.00-31500.00,49.50-65.00,0.940,3.770,1.890,0.349,0.064,1.017,0,0,400,512,0,0

(The remarked value is the default for arcade_31. Raise that value at your own risk)

Or, tell Switchres not use 512p:

monitor custom
crt_range0 31400.00-31500.00,49.50-65.00,0.940,3.770,1.890,0.349,0.064,1.017,0,0,400,480,0,0

(if you put that in the vertical.ini file it will work and still don't affect Irem games, MK, etc.)

Thank you I'd not put 2 and 2 together and seen my issues were on vertical games. Sorry about that. This modeline subject is rather confusing to a layman.

May I ask, is this also why some of these games are running at lower Hz than they should? I think it is, but would like to check 

In reply to haynor666, I'm running entirely horizontal (CRT weighs a tonne, no way I can rotate it).

[Calamity]

May I ask, is this also why some of these games are running at lower Hz than they should? I think it is, but would like to check 

Yes, that's what I was trying to explain.

[Chainsaw]

Thank you. I'm trying to wrap my ahead around all this. Being new to this all, it's very complicated. I have no idea where the KHz numbers are coming from, I'm from a PC background so I'm fine with Hz and resolutions, but in CRT land I can't see how relates to the other.

So I appreciate you patience 

I ran some tests to day. I raised the upper value of the crt range from 31500 to 32800 - any higher and the signal failed. This gave me a few extra Hz, so on on of the 60hz games I was having issues with, I could run them at 58hz (with 512 vertical res).

Then as you suggested, I tried a vertical.ini file with a limit of 480 - instant success Not only are the games running at the correct speed, they look a whole lot better as well. Thank you

As my monitor can apparently hit 32800, is it worth keeping that number with a custom monitor setting, or should I remain at 31500?

Thanks again, I'm so happy things are looking better and running correctly.

[Calamity]

As my monitor can apparently hit 32800, is it worth keeping that number with a custom monitor setting, or should I remain at 31500?

I'd restore the old value, it'll be safer.

The maths involving modelines are very simple. When you want a rough estimation of the horizontal frequency required for a given mode, just do:

horizontal_freq_in_kHz = vertical_resolution x 1.10 x vertical_refresh_in_Hz / 1000

So, 512 x 1.10 x 60 / 1000 = 33.79 kHz, that is well beyond your monitor's specs.


In the R-Type case, because it's 55 Hz:

512 x 1.10 x 55 / 1000 = 30.97 kHz, that is fine.


The 1.10 factor is applied here to account for the 10% extra blanking lines required. Not very accurate but it's good for an estimation and easy to remember.

[Chainsaw]

That is great. Thank you for taking the time to explain this. I had no idea what the KHz value meant in relation to anything else, and now I can see where it comes from things are starting to click into place for me.

As always, you're a star Calamity. Thank you 

[haynor666]

[mistake]