VGA cards use double scan lines for the 200 and 240 vertical resolutions. So in that case normal2x scaling would be the closest to a real vga monitor.

Thanks, that makes sense and certainly seems to be what I'm seeing here.

How about CGA and EGA games? My family did have a CGA PC years ago, but I honestly can't remember how the games should look, should they have those big thick 15khz type scanlines if played on an actual CGA PC and monitor?

I think CGA actually used 200 scan lines, so you wouldn't use normal2x scaling. But I haven't seen an actual CGA monitor for a long time so you should better wait for someone else to respond who owns an original CGA monitor…

If you don't want scale2x all the time, you'll want to try linewise vga emulation and vgaonly which will do the double-scanned mode more faithfully (i.e. games that switch palettes after specific scanlines, scrolling parts). This is not the default as it's slower and is more meant for edge-cases where the standard HLE S3 Trio emulation fails.

Sounds good, how do I do that?

BuckoA51 wrote on 2019-12-28, 19:04:

How about CGA and EGA games? My family did have a CGA PC years ago, but I honestly can't remember how the games should look, should they have those big thick 15khz type scanlines if played on an actual CGA PC and monitor?

Yes, CGA and EGA don't do any native double-scanning so 200-line modes use true 15 KHz.

That's great thanks. I guess CGA and EGA run on a VGA card must have been doublescanned by the card for monitor compatibility then? Effectively how you remember these games depends on what kind of PC you played them on.

BuckoA51 wrote on 2019-12-28, 18:38:

I'm fortunate enough to have a tri-sync CRT monitor attached to a PC I use for Groovy mame and Dosbox with CRT emudriver. […]
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I'm fortunate enough to have a tri-sync CRT monitor attached to a PC I use for Groovy mame and Dosbox with CRT emudriver.

To set up Dosbox I added the following modes to my CRT emudriver setup

720x480 @ 60.000000
360x480 @ 60.000000
720x400 @ 70.000000
360x400 @ 70.000000
720x350 @ 70.000000
360x350 @ 70.000000
720x240 @ 60.000000
360x240 @ 60.000000
720x200 @ 70.000000
360x200 @ 70.000000
640x400 @ 70.000000
320x400 @ 70.000000
640x350 @ 70.000000
320x350 @ 70.000000
640x240 @ 60.000000
320x240 @ 60.000000
640x200 @ 70.000000
320x200 @ 70.000000

This seems to have had the desired effect and Dosbox is definitely switching resolutions when I play games.

However I'm a little confused as to the scaling setting in Dosbox, should I be using none or Normal2x as the scaler? Should it be Normal2x for CGA, EGA and VGA titles?

If I use none, then CGA, EGA and VGA games I've tried run in 15khz with 15khz scanlines. Sometimes that does look cool, I particularly liked the scanline effect on Jazz Jackrabbit but I don't think VGA games should be doing that. Scanlines should be thinner or not there at all depending on the monitor... my memory is fuzzy but weren't the VGA low res modes line doubled by the PC or something?

As for CGA or EGA, did they have 15khz type scanlines at lower resolutions? It's been so long I honestly can't remember.

Thanks for any advice and Happy Christmas!

In my opinion, the best is using winmodelines, create 320x200 70hz doublescan, 320x240 60hz doublescan, 1280x800 60hz for EGA and CGA, and 720x348 50hz for hercules

the doublescan modes for VGA, just scaler=none

For EGA and CGA a scaler=scan4x will use 1280x800 and using a high resolution will eliminate the original scanlines, and in my opinion give a much close feeling as a real 15khz screen for example, at least in my 14 CRT

hercules well, i will recommend add some back and front porch, to make a small screen, give a much authentic feel

BuckoA51 wrote on 2020-01-13, 10:42:

That's great thanks. I guess CGA and EGA run on a VGA card must have been doublescanned by the card for monitor compatibility then? Effectively how you remember these games depends on what kind of PC you played them on.

Correct! Also some CGA games would get broken colors and/or text characters (certain graphical textmode games) in the process.