VGA CRT and ao486

[geiger9]

So the 486 core uses a resolution of 720x400 - fine, cool. I tried using direct video and my monitor would not accept the signal.

Now when I connect the same monitor to my Win98 rig and turn on the computer, the OSD reports that the computer is outputting 720x400 just after the BIOS screen but before Win98 finishes loading. So if my monitor can handle that resolution, why won't it accept it from the MiSTer?

[Chris23235]

Don't you have to specify an output-resolution in the MiSTer.ini even when using direct video?

[geiger9]

Don't you have to specify an output-resolution in the MiSTer.ini even when using direct video?

I thought that was only if you were using the scaler. I thought direct video meant outputting whatever resolution the core was designed for and to hell with your display.

Here's something else: the github page for the 486 core says it outputs a horizontal frequency of 44.95kHz and a vertical frequency of 60.0Hz. When my monitor tells me the signal is out of range, it says the incoming signal is 15.8khz horizontal and 60hz vertical. What's up with that?

[lister_of_smeg]

Don't you have to specify an output-resolution in the MiSTer.ini even when using direct video?

I thought that was only if you were using the scaler. I thought direct video meant outputting whatever resolution the core was designed for and to hell with your display.

The scaler is forced on in the ao486 core IIRC.

[callanabrown]

If you look down a few posts, you'll see a custom version that mentions automatic switching - it can go between 720x400 and 320x200 (640x400) which works great with VGA CRTs. I have been using this one a lot.

[akeley]

As @callanbrown says, it works very well: viewtopic.php?f=13&t=2375

[geiger9]

Thank god someone compiled this into a file that I can use. I am so out of my depth when using github. I have no idea how to compile something. I will certainly try this. Thanks!