4:3 ratio vs 16:9 on LCD

[AmigaHope]

Originally Posted by Marchie

Correct me if I'm mistaken, but neither NTSC or PAL are 4:3 resolutions (if considered as square-pixel resolutions) they both require non-square pixels to fit a 4:3 screen. No?

NTSC and PAL are analog on the horizontal access and don't have discrete pixels -- just discrete lines (so you could say it's digital on the Y axis). Consequently you can't define the aspect ratio in pixels -- the aspect ratio is 4:3 in screen dimensions.

So when you use an NTSC or PAL mode on the Amiga, it's still 4:3 aspect ratio in screen dimensions since that's how the display system is defined -- so yes you get non-square pixels. Especially in hires/non-laced modes with super skinny pixels (default Workbench for instance)

Since pretty much all displays at the time were 4:3, if your software is running in a mode that's pumping out x lines of video, its display should be sized to a 4:3 ratio. This includes most of those weird PAL games that only use an NTSC-sized section of the screen and just draw tons of black lines at the bottom -- the art is usually drawn assuming a PAL display and the black lines at the bottom are meant to be visible -- if you resize the "used-for-visuals" area to fill the screen then everything looks squashed vertically.

And of course if you're viewing it on any other sort of aspect ratio display (say 16:9), you'll want to keep the ratio of the transmitted area to 4:3 -- so for those weird games you might get a black bar at the bottom in addition to the black bars on the side. That's still the way it's meant to be seen (though, potentially) you could use the extra screen real estate to zoom in on the "drawn" area on those weird "letterbox PAL" games.