PC graphics modes below 640x480 resolution have non-square pixels. A notable exception is when mode 13h (320x200x256) is register-tweaked to 320x240, AKA Mode X, but relatively few games use it. The obvious reason why games sometimes have "distorted" shapes is that an artist created the graphics using square pixels while the game uses non-square pixels, or vice versa, it's really that simple.

A 4:3 ratio display is the "period correct" appearance of a CRT monitor, but don't overthink it -- just choose your preferred appearance.

The only period correct for the 'correct' likely-amiga-drawn square pixels in 320x200 would be on old laptops as the 4:3 stretching on LCDs didn't happen until the late 90s. 😀

There's also some games that get aspect corrected that shouldn't with odd <480 modes that run on 60hz, like Jazz, Incredible Machine, etc... that's separate from the hired-an-amiga-artist issue.

Thanks for those comments, which are a big help. It seems that the discrepancy caused by DOS games using Amiga artists means that to be period accurate to a CRT, it should be enforced 4:3 aspect ratio every time, despite things looking a bit off.

It is interesting that on some Macintosh and Amiga versions (i.e. most early LucasArts adventures) the aspect ratio of the original art was preserved, with letterboxing at the top and bottom of the image. So it was displayed in the proportions of the original artwork, even on a 4:3 CRT. That is another reason that I was inclined to view the 'un-corrected' image as the most appropriate.

There are some older EGA games, i.e. Balance of Power (DOS) and Sim City, which also exhibit the issue and just look totally off. I doubt the black and white graphics for Balance of Power were drawn on an Amiga, but if this is what the games would have looked like on a CRT, fair enough then. 😀

almeath wrote on 2023-04-11, 23:38:

There are some older EGA games, i.e. Balance of Power (DOS) and Sim City, which also exhibit the issue and just look totally off. I doubt the black and white graphics for Balance of Power were drawn on an Amiga, but if this is what the games would have looked like on a CRT, fair enough then. 😀

That's a known bug (aspect ratio calculation is incorrect for EGA modes).

It's like history repeating itself: Aspect ratio in SimCity for DOS

There is an issue with aspect correction of 350-line modes, but as I mentioned in the previous thread, that issue only affects the machine=ega setting.

Thanks, I totally forgot that I had previously raised SimCity as an example.

And thanks @jmarsh, I had been thinking solely of the machine type setting, but did not realize that Balance of Power, being an EGA-only game, was just forcing a switch to that mode, regardless if I selected vgaonly or svga_s3 machine types. So the bug definitely affects the mode, not just the machine=ega setting. I will leave it at that.. but hoping one day for a fix to that bug.

Once again, the aspect ratio issue DOES NOT affect (S)VGA machine types -- it only affects the EGA machine type. Balance of Power, SimCity, and any other games that use mode 10h (640x350x16) have accurate aspect correction if you simply stay with the default machine=svga_s3 setting. I hope this is perfectly clear now.

BTW, Balance of Power is not "EGA-only". Like many Windows programs, it displays according to the video driver that Windows (1.x or 2.x in this case) has been configured to use.

ripsaw8080 wrote on 2023-04-12, 06:01:

BTW, Balance of Power is not "EGA-only". Like many Windows programs, it displays according to the video driver that Windows (1.x or 2.x in this case) has been configured to use.

Thanks, I had forgotten that Balance of Power is running on top of Windows 1.x, so I will check what driver is being used within that environment.

It seems that the discrepancy caused by DOS games using Amiga artists means that to be period accurate to a CRT, it should be enforced 4:3 aspect ratio every time, despite things looking a bit off.

Well, even back in the day some (or many) CRT monitors had buttons with which you could stretch and squeeze the image as you like, thus correcting such discrepancies, so period accurate would not mean to force it to 4:3 no matter what. True, 320x200 was meant to fill a 4:3 screen, but I agree with what has already been said: Don't overthink it 😉

As a side note, one of my oldest computers, a Sinclair QL, also had this problem - the builtin basic interpreter had a 'draw circle' command which always made an egg-shape. But the monitors also had a stretching dial to make it round and then all was looking good. I think I readthe initial intent was to equip those machines with an early LCD screen that had suitable pixels to compensate for the eggy roundels, but this monitor never materialized.

The only issue I had was in a discussion with someone on Mobygames, when I wanted to submit a corrected screenshot for the QL flight simulator I had, when only eggs were allowed (and it still is).

Kalle wrote on 2023-04-12, 09:17:

Well, even back in the day some (or many) CRT monitors had buttons with which you could stretch and squeeze the image as you like, thus correcting such discrepancies, so period accurate would not mean to force it to 4:3 no matter what. True, 320x200 was meant to fill a 4:3 screen, but I agree with what has already been said: Don't overthink it 😉

Yes, that makes sense. On the Macintosh, many games (including most of the Lucasfilm/LucasArts adventures) did not stretch the 320x200 image to fill the 4:3 screen, but just displayed it with letterboxing at the top and bottom of the image. Whether manual correction was needed would then depend on the source art and one's preference as to what looked correct.

On the Macintosh, many games (including most of the Lucasfilm/LucasArts adventures) did not stretch the 320x200 image to fill the 4:3 screen, but just displayed it with letterboxing at the top and bottom of the image.

Noticed the same on the Amiga. These images are from footage shot back in early 1996. Dune II is shown with square pixels and the lower part is simply black, the buildings look square. On the PC, it looks a bit stretched when it fills the screen.

Now with the Amiga, there were also differences for PAL and NTSC, similar to consoles. PAL offered a higher resolution, which is the reason many games on NES, SNES etc. look squished in countries where PAL is used. Basically the PAL versions were displayed the wrong way and even ran slower, but that's how it was. My Amiga was a PAL unit, possibly Dune II looked different on an NTSC Amiga. Also I used a TV rather than a monitor. And no idea where the artwork was created. Actually the artwork on the Mentat's screen (like the planets) and the ornaments on the frame borders look correct when filling the 4:3 screen and squished with square pixels, thus my guess is that one artist had the 4:3 screen in mind while the other didn't, probably the whole topic was too complex or confusing even back then, and/or people didn't care as much as we do now.

Kalle wrote on 2023-04-14, 10:00:

Noticed the same on the Amiga. These images are from footage shot back in early 1996. Dune II is shown with square pixels and th […]
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On the Macintosh, many games (including most of the Lucasfilm/LucasArts adventures) did not stretch the 320x200 image to fill the 4:3 screen, but just displayed it with letterboxing at the top and bottom of the image.

Noticed the same on the Amiga. These images are from footage shot back in early 1996. Dune II is shown with square pixels and the lower part is simply black, the buildings look square. On the PC, it looks a bit stretched when it fills the screen.

Dune II Amiga (1).png
Dune II Amiga (2).png

Now with the Amiga, there were also differences for PAL and NTSC, similar to consoles. PAL offered a higher resolution, which is the reason many games on NES, SNES etc. look squished in countries where PAL is used. Basically the PAL versions were displayed the wrong way and even ran slower, but that's how it was. My Amiga was a PAL unit, possibly Dune II looked different on an NTSC Amiga. Also I used a TV rather than a monitor. And no idea where the artwork was created. Actually the artwork on the Mentat's screen (like the planets) and the ornaments on the frame borders look correct when filling the 4:3 screen and squished with square pixels, thus my guess is that one artist had the 4:3 screen in mind while the other didn't, probably the whole topic was too complex or confusing even back then, and/or people didn't care as much as we do now.

Cool setup, I do collect these little black 90s TVs myself. They're really robust and provide an old school CRT feeling. 😎👍

PAL.. The problem wasn't so much PAL itself, but the fact that both USA and Japan were NTSC countries and big players in the video game business.

That's why we in the PAL countries had to suffer most of the time, games were rarely corrected to fit PAL resolution and speed (50 Hz).
The Mega Drive game "Ristar" was one of the exceptions.
https://www.mobygames.com/game/11538/ristar/trivia/

Sonic 2 also had corrections, so that the music and game ran at same speed both in PAL/NTSC consoles (or rather, 50Hz/60Hz timing).

That being said, back in the 90s, black bars were common on PAL consoles, but they weren't a must. Video monitors like the Commodore 1702/1701 had adjustment knobs for v-size, h-size, v-hold, h-hold.
Personally, I had made use of that and stretched my NES/SNES picture to full height.
The little slow down was the only drawback I experienced back then. 🙂

Edit: There's else something that comes to mind.
Some painting programs had issues drawing round circles because the math used expected square pixels.
The result was an oval on a 320x200
-like resolution.
Maybe something similar happened with squares, the math simply didn't take uneven pixels into account. Thus, a rectangle appeared.

Edit: Another idea - maybe one of the artist did use the knobs on a Commodore monitor to stretch the image, as I did ?
If I was serious about my Amiga, I would have done that (fixing aspect ratio).

Those are all good points, and all likely to be valid to varying degrees, depending on when/where/how the specific game was created. I saw some old footage of artists drawing using Deluxe Paint back in the 80s/90s on the Amiga, and the circles were coming out as ellipses on their CRT monitors. As already mentioned above, having several artists working on the same software at once, possibly on different systems and in different geographical areas, would have compounded the issue. I suspect that is why in some games, for example Loom, there are some scenes where it looks like 4:3 correction is needed, and others that do not. There is probably no correct method to use, unless one was to use a CRT and then manually adjust at different points in the game. So the comments about not over-thinking it are very good advice.. just pick a look that you prefer and stick with it. I've determined my favorite settings on a per-game basis, some in 4:3 and others left 'stretched'. I tend to leave the UK developed games, such as Simon the Sorcerer 1 and 2, and Beneath a Steel Sky in the uncorrected ratio. Lure of the Temptress is another one that comes to mind. LucasArts games are mixed, but I decided to play the Mac versions in their original uncorrected configuration and leave the PC versions in 4:3.

I'm sorta purist then it comes to this stuff, always wanting to experience 'like the devs intended', so I too used "true" setting for some years like a devoted DOSBox pilgrim. OP is basically me some years ago.

Short answer is 'correct' aspect ratio is usually "false" until you come across oval circles/spheres, then it's "true". The setting name itself is misleading. Real mind bender is good ol' Privateer (I think?) where planets are of right proportions but panel instruments are oval, and the opposite when you switch aspect in conf. That finally made me realize 'correct' aspect is what looks right to you. When case like Privateer arises then you go with what annoys you less.

The whole thing is mostly because modern LCDs have square pixels whereas on olde CRTs they were tall rectangles. So on CRT 320x200 resolution was 4:3 proportion while on todays LCD it's 16:10 (with black bars on sides if LCD is 16:9). Another cause was lack of coordination between programmers and artists, effectively nullifying 'like devs intended' mantra. On sub-SVGA resolutions it's simply not possible to recreate CRT 'look' on a modern square pixel LCD so we have to improvise.

It's a nice rabbit hole to revisit, occasionally these topics pop up and it always puts a grin on my face. Nice to see people still care about these things. Here's a nice link that demonstrates some on the aspect ratio shenanigans, just scroll past Jill of the Jungle part.
http://nerdlypleasures.blogspot.com/2013/10/3 … for-ibm-pc.html

See you again OP, if/when you catch up to audio side of things... 😀

As already mentioned above, some artists understood that their game would be displayed on a 4:3 monitor, and adjusted their art accordingly. Others did not, and that's why their games look off in that aspect ratio. There were also some multi-platform games which had to make compromises due to the different resolutions of their target systems.

BTW, this isn't limited to PC games. There are many SNES and Sega Mega Drive titles which suffer from the same issue. The Displaced Gamers channel has a couple of interesting videos on this subject regarding DOS as well as SNES games.

Nilex wrote on 2023-04-15, 09:39:

See you again OP, if/when you catch up to audio side of things... 😀

Thanks - I have already gone down that rabbit hole 😉

Joseph_Joestar wrote on 2023-04-15, 10:37:

As already mentioned above, some artists understood that their game would be displayed on a 4:3 monitor, and adjusted their art accordingly. Others did not, and that's why their games look off in that aspect ratio. There were also some multi-platform games which had to make compromises due to the different resolutions of their target systems.

BTW, this isn't limited to PC games. There are many SNES and Sega Mega Drive titles which suffer from the same issue. The Displaced Gamers channel has a couple of interesting videos on this subject regarding DOS as well as SNES games.

Thanks to everyone for their insights on this thread, I know it treads some old ground for some, but I found the feedback extremely useful.

almeath wrote on 2023-04-18, 12:37:

Nilex wrote on 2023-04-15, 09:39:

See you again OP, if/when you catch up to audio side of things... :)

Thanks - I have already gone down that rabbit hole ;-)

I read your signature immediately after I posted that (but of course) and felt so dumb for the rest of the day lol.
Rabbit hole is indeed a good term for it but valuable goodies await those who dare crawl to the end of it :)