If you can make Windows stretched like that, then dosbox can be too. First, set your Windows to 1024x768 (or some other 4:3 video mode), and then find out your monitor or graphics card settings to make that stretched across the screen. Your monitor might have a scaler setting called "stretch" as opposed to "keep aspect". Same with your graphics card settings. The availability of these settings could depend on whether you're using VGA or a digital conncetion like DVI-D, HDMI or DisplayPort.

Then, switch back to 1920x1080 on your desktop without touching those important settings that made the previous video mode stretched. Set Dosbox aspect=true, output=ddraw or opengl or overlay, and fullresolution=1024x768. After that Dosbox should be stretched across the screen.

Thanks for your quick response, ripa! 😀

I've still not managed to flip it right, though. I've managed to get my monitor on a [pixel-stretched] 1024x768 resolution, but even now, I don't get the margin offsets right. This here (http://i.imgur.com/2JGb7pM.png) is the splash screen. When I hit ALT+ENTER, I want blue to start at the upper left corner, but it refuses to do so. Even with 1024x768 (4:3) resolution, the upper ~3/4 inch is black padded á la letterboxing. Look, when I do fullresolution=desktop when I'm on 1080p resolution, it looks like this (http://i.imgur.com/VOMkcxA.png) when I hit ALT+ENTER. As you can see the picture is now pillarboxed; black padding to the left/right. Any more ideas? Does anyone around here actually have a 16:9 monitor (with a 1920x1080 native resolution) whom could report in that he/she has actually managed to stretch DOSBox _fully_ across the screen, then I would be more rest assured that it's not totally hopeless.

Cheers!

I forgot that my first suggestion doesn't work for text mode. However, once you're in any game (except text-mode games 😜), it should be correct.

If you want text modes to also be stretched across the whole screen, then I think additionally adjusting the following should help:
fullresolution=original
scaler=normal2x forced

"output" doesn't matter very much when fullresolution=original. If this doesn't work, then I think you'll have to find a patched version of dosbox that applies the aspect=true also setting to text modes.

You are amazing. To be honest now, I was fiddling around more, and went for a screenshot (http://i.imgur.com/6fC9TVi.png to show you my result with fullresolution=1024x768, i.e. visible letterboxing, which — logically — is messing up the (by developers) desired aspect ratio even more than just stretching 4:3 to a full 16:9. Anyways, while I was fiddling around with this i thought to myself that I could also try jumping an actual game, so I popped a real classic from my childhood (http://i.imgur.com/BhTVskM.png). Now, to my sudden surprise, the letterboxing was now history, and screenshot/game resolution nailed their intended 1024x768. The game was fully stretched. This (to be honest) first got me thinking that I had done some real shameful mistake in my "logic" about the (ANSI?) text of that splash, i.e. so that it per nature could never stretch fully.

However, then I went back here to post my happy results with the actual game, which was good enough to me (I don't intend sitting in EDIT.COM writing stuff in wide-screen mode). It was then a great and happy surprise that you also had news. I tried your suggested lines, and now everything works absolutely _flawless_. Everything is fully stretched (http://i.imgur.com/mRuvgly.png); games, DOS, everything. It seems to pick 1280x800 for resolution, which serves this purpose great.

Big thanks for quick responses and great help overall.

Have a good weekend! 😀