dosbox-X fails EGA torture test

[Corona688]

Describe the bug

So, there exists an EGA torture test published by IBM itself. This presumably is running on a real machine: https://www.youtube.com/watch?v=czfGt5iNuSQ
And the disk image on archive.org https://archive.org/details/ega-fland

Notably, the working version explains how everything works as it does it. Seems like an excellent opportunity to improve the EGA routines.

Steps to reproduce the behaviour

note: fland requires itself to be run from the B drive. Anything else will cause file not found errors. So the correct running procedure is something like:

imgmount b -t floppy c:\fland.img
b:
fland.exe

Expected behavior

fland does load and run recognizably -- congrats! -- but has a variety of issues. To begin with, there are flickering lines. When it gets to the map section, the 'cursor' is missing, the animations are wrong, and the text section below never appears.

What operating system(s) this bug have occurred on?

Windows 10

What version(s) of DOSBox-X have this bug?

freshly downloaded?

Used configuration

Output log

Additional information

No response

Have you checked that no similar bug report(s) exist?

• I have searched and didn't find any similar bug report.

Code of Conduct & Contributing Guidelines

• I agree to follow the code of conduct and the contributing guidelines.

[rderooy]

Did you search for similar issues?
#3460

[MX9000]

The video description says that it's running in DOSBox-X 2022.08.0 under Ubuntu 18.04, not on real hardware.

[Corona688]

I searched for similar issues, including a search for EGA and a search for fantasy. Nothing relevant.

I have added machine=ega200 to the config file as this bug suggested. No change in behavior at all.

It will not allow me to attach my config file, so I've copied it to a txt

dosbox-x.conf.txt

[Corona688]

Commandline -set machine=ega200 allows the intro to work. I'm not sure what the config file equivalent is.

It seems to freeze afterwards.

[maron2000]

Seems working fine, just set machine=ega200 as suggested in #3460 that you somehow mention not relevant.
Same software, same solution.

Command.000-1.mp4

[Corona688]

I mention that I found no relevant results in several searches, not that this wasn't relevant.

May I have your dosbox.conf ? Mine shows the red scroll, and one frame of the map, then seems to freeze after that.

[Corona688]

after 'press any key to continue' it freezes here.

[joncampbell123]

IBM fantasy land? I remember adding machine=ega200 about 2-3 years ago specifically for this program, because the game seems to ASSUME 200-line EGA output.

[Corona688]

Correct, and knowing this I get a correct opening screen, though problems after it. Mine freezes on the map while his does not.

Though 'freeze' may be the wrong word. Some characters still animate, implying animation is still happening, but the demo does not play.

His is running from a:\ however, while mine insists on running from b:, making me wonder if we have the same disk image or not. I got mine from archive.org

[Corona688]

Got it working. One has to boot the disk, not just mount it. Even then there's some b / a confusion.

[rderooy]

It is even specifically mentioned on the wiki, including a reference to fantasy land.
https://dosbox-x.com/wiki/Guide%3AVideo-card-support-in-DOSBox%E2%80%90X#_ega_with_an_mda_or_cga_monitor

Fantasy Land is very peculiar. It will have the same issues as you encountered on most retro PC setups, even if you have an authentic IBM EGA adapter. Only if you use a 200-line CGA monitor with an EGA card, will you get the correct output. That is exactly what the ega200 setting emulates. An EGA monitor simply does not support the 200 line mode this demo tries to use.

[maron2000]

Just as a fact, I used the image mentioned In the link above (why should anyone doubt that? lol) but the video is recorded without booting the image.
IMGMOUNTed on A drive, and launched the demo.

[joncampbell123]

It is even specifically mentioned on the wiki, including a reference to fantasy land. https://dosbox-x.com/wiki/Guide%3AVideo-card-support-in-DOSBox%E2%80%90X#_ega_with_an_mda_or_cga_monitor

Fantasy Land is very peculiar. It will have the same issues as you encountered on most retro PC setups, even if you have an authentic IBM EGA adapter. Only if you use a 200-line CGA monitor with an EGA card, will you get the correct output. That is exactly what the ega200 setting emulates. An EGA monitor simply does not support the 200 line mode this demo tries to use.

EGA monitors absolutely support 200-line modes. 320x200 and 640x200 2/4/16-color graphics modes are sent to the monitor in exactly the same way as CGA RGBI signals. The 200-line modes are also compatible with CGA monitors as well.

EGA cards lack the hardware line doubler that MCGA and VGA cards do and will not emit 200-line graphics/text mode as 400-line.