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Isn't that the right DOSBOX behavior? I think it should maintain the original aspect ratio as it looked in the old CRT monitors. I remember drawing circles in C

Isn't that the right DOSBOX behavior? I think it should maintain the original aspect ratio as it looked in the old CRT monitors. I remember drawing circles in CRT monitors on IBM PCs and the circles did look vertically squished. Why should DOSBOX or FFMPEG alter that original aspect ratio? Altering that artificially would be like lying about what the real output looked like in the good old days.

klodolph 7y ago
If you use DOSBox with default settings, the pixel aspect ratio will be square. Old PCs, as you remember, had non-square aspect ratios, and so the graphics will look incorrect, they will look squashed horizontally.
- susam 7y ago
  I am running DOSBox with default settings. I draw a square and then a circle with these lines of Logo code: REPEAT 4 [FD 1 RT 90] REPEAT 360 [FD 1 RT 1] I find that both the square and the circle appear squashed. On measuring the pixel height and width of these figures as they appear on my desktop, I see that the square is 400 pixels in width and 320 pixels in height. That's an aspect ratio of 5:4. Similarly, the circle is 460 pixels in width and 364 pixels in height. That's an aspect ratio of 1.26:1. I find the same aspect ratio in full screen (Alt + Enter) mode too. In the full screen mode, the square is 200 pixels in width and 160 pixels in height and the circle is 230 pixels in width and 182 pixels in height. Here are the screenshots: - https://imgur.com/l9YpTqp https://imgur.com/l9YpTqp - https://imgur.com/WTwfSzq https://imgur.com/WTwfSzq - https://imgur.com/CjMYJN6 https://imgur.com/CjMYJN6
  - Crinus 7y ago
    Edit the dosbox configuration file and change aspect=0 to aspect=1, it'll resize the output to be aspect correct but it might be a bit blurry (IIRC the scale3x scaler will do a pixel-scale and then that will be bilinearly resized, giving mostly crispy pixels with a bit of in-between bleeding which is probably the best you can get with an LCD monitor)
    - susam 7y ago
      With aspect=1, the square is 400 pixels high and 384 pixels wide, not exactly an aspect ratio of 1:1 but quite close, 1.04:1. The parent of my earlier comment, i.e., the one by klodolph, claims that the pixel aspect ratio would be square by default in DOSBox, so I thought I would verify it once. As per my experiments, that does not seem to be the case.
      - fireattack 7y ago
        I think what he meant is that, The pixels are square in DOSBox, but the graphics from these old programs are designed for non-square pixel ratio. So, if you display it with square pixel, the display aspect ratio will be wrong. (Of course, this still contradicts with what neatcoder said, but I can't remember if these programs were "squished" on CRTs or not.)
        susam 7y ago
        See these screenshots of SCREEN 2 in GW-BASIC running in DOSBox: - https://imgur.com/NZUGL1e https://imgur.com/NZUGL1e (aspect=0) - https://imgur.com/rnQOfA4 https://imgur.com/rnQOfA4 (aspect=1) The one with aspect=1 looks very odd.
        klodolph 7y ago
        The one with aspect=1 looks incorrectly configured. There are a number of different graphics modes, they have different pixel aspect ratios, you can also adjust the monitor, it is possible that back in school you were using a different mode or a different monitor. I think there are some other factors that can affect this.
        susam 7y ago
        Back in school, I played with SCREEN 0, SCREEN 1, and SCREEN 2 documented in the GW-BASIC user manual. Here's a copy: http://www.antonis.de/qbebooks/gwbasman/screens.html http://www.antonis.de/qbebooks/gwbasman/screens.html . The reason why I stick to aspect=0 (the DOSBox default) is that this is the one that more closely reproduces the experience I had with the CRT monitors at school. I agree that the actual monitor or the way it is configured could affect the aspect ratio we observe. Perhaps ours was not adjusted to produce 1:1 square while working with IBM Logo. But it did produce 1:1 square with GW-BASIC SCREEN 1 mode.
NikkiA 7y ago
good CRT monitors would auto-sync and get the aspect ratio right.

klodolph 7y ago

If you use DOSBox with default settings, the pixel aspect ratio will be square. Old PCs, as you remember, had non-square aspect ratios, and so the graphics will look incorrect, they will look squashed horizontally.

susam 7y ago
I am running DOSBox with default settings. I draw a square and then a circle with these lines of Logo code: REPEAT 4 [FD 1 RT 90] REPEAT 360 [FD 1 RT 1] I find that both the square and the circle appear squashed. On measuring the pixel height and width of these figures as they appear on my desktop, I see that the square is 400 pixels in width and 320 pixels in height. That's an aspect ratio of 5:4. Similarly, the circle is 460 pixels in width and 364 pixels in height. That's an aspect ratio of 1.26:1. I find the same aspect ratio in full screen (Alt + Enter) mode too. In the full screen mode, the square is 200 pixels in width and 160 pixels in height and the circle is 230 pixels in width and 182 pixels in height. Here are the screenshots: - https://imgur.com/l9YpTqp https://imgur.com/l9YpTqp - https://imgur.com/WTwfSzq https://imgur.com/WTwfSzq - https://imgur.com/CjMYJN6 https://imgur.com/CjMYJN6
- Crinus 7y ago
  Edit the dosbox configuration file and change aspect=0 to aspect=1, it'll resize the output to be aspect correct but it might be a bit blurry (IIRC the scale3x scaler will do a pixel-scale and then that will be bilinearly resized, giving mostly crispy pixels with a bit of in-between bleeding which is probably the best you can get with an LCD monitor)
  - susam 7y ago
    With aspect=1, the square is 400 pixels high and 384 pixels wide, not exactly an aspect ratio of 1:1 but quite close, 1.04:1. The parent of my earlier comment, i.e., the one by klodolph, claims that the pixel aspect ratio would be square by default in DOSBox, so I thought I would verify it once. As per my experiments, that does not seem to be the case.
    - fireattack 7y ago
      I think what he meant is that, The pixels are square in DOSBox, but the graphics from these old programs are designed for non-square pixel ratio. So, if you display it with square pixel, the display aspect ratio will be wrong. (Of course, this still contradicts with what neatcoder said, but I can't remember if these programs were "squished" on CRTs or not.)
      - susam 7y ago
        See these screenshots of SCREEN 2 in GW-BASIC running in DOSBox: - https://imgur.com/NZUGL1e https://imgur.com/NZUGL1e (aspect=0) - https://imgur.com/rnQOfA4 https://imgur.com/rnQOfA4 (aspect=1) The one with aspect=1 looks very odd.
        klodolph 7y ago
        The one with aspect=1 looks incorrectly configured. There are a number of different graphics modes, they have different pixel aspect ratios, you can also adjust the monitor, it is possible that back in school you were using a different mode or a different monitor. I think there are some other factors that can affect this.
        susam 7y ago
        Back in school, I played with SCREEN 0, SCREEN 1, and SCREEN 2 documented in the GW-BASIC user manual. Here's a copy: http://www.antonis.de/qbebooks/gwbasman/screens.html http://www.antonis.de/qbebooks/gwbasman/screens.html . The reason why I stick to aspect=0 (the DOSBox default) is that this is the one that more closely reproduces the experience I had with the CRT monitors at school. I agree that the actual monitor or the way it is configured could affect the aspect ratio we observe. Perhaps ours was not adjusted to produce 1:1 square while working with IBM Logo. But it did produce 1:1 square with GW-BASIC SCREEN 1 mode.

NikkiA 7y ago

good CRT monitors would auto-sync and get the aspect ratio right.