In 320x200, pixels have a 1.2:1 aspect ratio
320x200 is actually 320x400 where each line is display twice

LCD sceen have some streching algorithm for standard resolution and vga mode but for mode-X 320x200 picture is display incorrectly, unstreched or off center

I used to play vga games on a T2150CDRT: 640x480 laptop
Text mode were streched repeating some line between characters
VGA 320x200 was compressed vertically with black bar at top and bottom

through dosbox in "native resolution" ( in a window) shows a "wrong" (streched) picture

Yep, use aspect=true along with a scaling output= setting to correct this.

The reason for 320x200 is quite simple btw.: 320x200=64000 so the window
fits into one segment (0xa000) whereas the 320x240 mode needs plane switching.

Thanks for the quick answers. So just to see if I got it right:

StickByDos wrote:

In 320x200, pixels have a 1.2:1 aspect ratio

This means that in 13h pixels are a little bit "higher", doesn't it?
So when I add that factor to the columns and lines I get an aspect ratio of 4:3:
320x1:200x1.2 = 320:240 = 4:3 (?)

I ask this because I have a LCD with a 4:3 resolution (1400x1050). So when I play a game with 320x200 resolution under plain dos in fullscreen mode (there is no other available anyway) apart of being somehow interpolated the aspect ratio should be the correct one?

i've always played 320x200 in a 4:3 aspect since the 80s

So I believe 320x200 is intended to be 4:3 all this long

From what I've seen it depends on the game. Even though all 320x200 games are intended to be played on displays with 4:3 ratio, you can see that in some games circle is circle, while in others circle is verticaly stretched on 4:3 ratio.
It also depends on how LCD handles 320x200 resolution (streching it to full screen, or adding black bars).

This means that in 13h pixels are a little bit "higher", doesn't it?

Yep.

I ask this because I have a LCD with a 4:3 resolution (1400x1050).
apart of being somehow interpolated the aspect ratio should be the correct one?

If the physical dimensions of your LCD are 4:3 and the interpolated image
fills the whole screen, the aspect ratio is correct. Most often the interpolation
sucks though.

you can see that in some games circle is circle, while in others
circle is verticaly stretched on 4:3 ratio.

Then either this is NOT a 320x200 mode (but some unchained mode most likely)
or they're drawing circles/images/whatever with aspect correction.

wd wrote:

Then either this is NOT a 320x200 mode (but some unchained mode most likely)
or they're drawing circles/images/whatever with aspect correction.

Yeah, that sounds logical. But still I'm confused, because I observed the same phenomenon as Miki Maus. The two images below are taken from Star Control 2 (original PC version) and the intro of Planet's Edge by using the dosbox / defend screenshot function (strg+f5). As far as I see screenshots taken this way are allways without aspect correction, so the resolution is 320x200 with square pixels and therefore with an aspect ratio of 16:10 (8:5). The screenshots should display a geometrically "wrong" image.

As expected poor earth in SC2 is compressed vertically (like a pumpkin).
But as you can see earth and moon in Planet's Edge are almost circles. And the game claimes itself to use 320x200, because that's the choice you get in the setup program. (you can choose between 320x200 for tandy, vga and ega display adapters). Furthermore, if you use aspect correction (to have the 4:3 aspect ratio) SC2's earth looks a little bit egg-shaped (the one of PE looks like a real egg)

What's the reason? Did I miss something?

And the game claimes itself to use 320x200

Well they claim that, no idea if it's true, they might even switch modes
to display some images.

What's the reason? Did I miss something?

The reason for what? If you're capturing screens you get the raw
image dimensions, ie. 320x200, which will usually display with wrong
ratio on any square pixel mode (paint program etc.)

wd wrote:

you can see that in some games circle is circle, while in others
circle is verticaly stretched on 4:3 ratio.

Then either this is NOT a 320x200 mode (but some unchained mode most likely)
or they're drawing circles/images/whatever with aspect correction.

Yes they are, as I was talking about games that use 320x200, at least that are dimensions of screenshots and games take whole screen. But the graphics for these games were drawn without taking into account pixel ratio (or they are conversion from other systems, etc.) so they look better without aspect correction. Some examples:

But the graphics for these games were drawn without taking into account pixel ratio

Yes but then you're talking about ellipses, not circles. I'm talking about circles
if they're displayed as circles on a real pc.
There are several games which got the aspect ratio of imagery wrong because
they assumed pixels to be square. Wonder if they ever looked at their games...

Mhm...

So the reason that i.e. the earth of the NWC logo is "eggy" when displayed with the common 4:3 ratio could be a programming error?
And what we see using dosbox (without aspect correction enabled) is what the designers wanted the game to look like, yet it never did at that time, because it was (dis) played on a standard 4:3 VGA screen? Is this really possible?

I don't know the game, but it surely is no programming error, more a
communication problem between the graphics department and the
game designers.

Monitors sold when these games were sold had controls to stretch or squeeze the image horizontally and vertically without distorting the pixels at all. Some games may do better letterboxed using the vertical control.

Great Hierophant wrote:

Monitors sold when these games were sold had controls to stretch or squeeze the image horizontally and vertically without distorting the pixels at all. Some games may do better letterboxed using the vertical control.

I agree. Programmers and graphic artists cared less about aspect ratios, because back then, everyone had crappy monitors. Standard VGA monitors needed manual adjustment after every mode switch. On most screens, the aspect ratio was wrong all the time, as people didn't bother fiddling with the controls as long as they got the whole picture on the screen.

Miki Maus wrote:

Yes they are, as I was talking about games that use 320x200, at least that are dimensions of screenshots and games take whole screen. But the graphics for these games were drawn without taking into account pixel ratio (or they are conversion from other systems, etc.) so they look better without aspect correction. Some examples:

Pinball Dreams, which you showed a screenshot of, was actually developed with square pixels in mind. The original game was released for the Amiga computer, while the PC DOS port is, well, a port.

wd wrote:

The reason for what? If you're capturing screens you get the raw image dimensions, ie. 320x200, which will usually display with wrong
ratio on any square pixel mode (paint program etc.)

Er, I believe Silent Loon actually asked why the globe on Planet's Edge is not displayed with wrong ratio.

Freddo wrote:

Miki Maus wrote:

Pinball Dreams, which you showed a screenshot of, was actually developed with square pixels in mind. The original game was released for the Amiga computer, while the PC DOS port is, well, a port.

As far as I know Pinball Dreams and Fantasies were both programmed and developed on PC, they were ported by REFLECTIONS to the Amiga. Dreams was launched on Amiga first at the behest of Commodore UK so that it could be included in an A1200 bundle pack (even though the game used no AGA features).

I've looked and can't find any evidence on the net that supports my memory but I remember this as being the case when I worked as games journalist and was sent early release copies of Dreams for PC and Amiga at the same time - some three months prior to the game's and the A1200's release.

dh4rm4 wrote:

As far as I know Pinball Dreams and Fantasies were both programmed and developed on PC, they were ported by REFLECTIONS to the Amiga. Dreams was launched on Amiga first at the behest of Commodore UK so that it could be included in an A1200 bundle pack (even though the game used no AGA features).

I've looked and can't find any evidence on the net that supports my memory but I remember this as being the case when I worked as games journalist and was sent early release copies of Dreams for PC and Amiga at the same time - some three months prior to the game's and the A1200's release.

Pinball Dreams was the first game to be developed by Digital Illusions (nowdays more known behind the Battlefield series), which back then consisted of a bunch of Amiga enthusiasts who had previously been releasing demos on the Amiga demo scene under the name The Silents. They later developed Pinball Fantasies and Pinball Illusions.

It was ported to PC by Spidersoft Limited, an inhouse game studio owned by 21st Century Entertainment Ltd who published the game.

If you start the DOS version of the game you will see the Spidersoft logo which isn't there in the Amiga version. I have rather strong memories of this game too, seeing how it was developed by Digital Illusions who started and stayed in this town until 1998 when they moved (first swedish developer I knew of too). And I was a huge Amiga fanatic then, and like now, we kids back then had immature platform wars and one of our strongest Amiga arguments were Pinball Dreams, and how crappy non-swedish the DOS port was.

Here an interesting user review of the DOS version too.

EDIT: there's some more info in the Trivia section of mobygames.

Actually, I wish to modify my opinion a bit. All PC compatible CRT monitors other than the first should have vertical size controls. Most people prefer their images to fill the screen. What kinds of images did people tend to see the most often on their screens? I would answer text, whether it be DOS or some other application. The CGA and VGA text modes use either 200 or 400 lines and their monitors are really able to display approximately 240 or 480 lines. Considering that older computer monitors were rarely larger than 15" viewable area, I would guess that most people did maximize the screen image.

Many developers, using a standard drawing algorithm designed for squarish resolutions, doubtless forgot that the unique characteristics of resolution and monitor on 320x200 modes required a different algorithm. The result may be ovular but not elliptical. Even so, a the difference between 200 and 240 lines and their multiples is only 20%, so any deviation from an ideal circle would not likely be unacceptable.