DOS ain't dead

> 1280x1024, which is 1.25:1 stretched on a 1.7777:1 laptop monitor screen).
> So, if there someway to detect additional VESA modes, will this fix that
> bug?
I only detect modes from a hard coded list.
If you want me to add extra resolutions just give me a list.

> Or are you referring to a completely different AR bug? Sometimes large
> images don't fit completely on screen when Zoom Out mode is selected in
> DOSView. The bottom is cut off / they only partially display. These large
> images do display fully when ZOOMed and scrolled, however.

On my list is a bug where zooming of portrait images and everything not 4:3 is not working as expected.
I tried to fix it recently but I could not wrap my head around the problem and ran out of time/motivation.

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> If you want me to add extra resolutions just give me a list.
OK, thanks. Will you consider adding these VESA resolutions:
1280x1024x32 (mode 0x11B)
1600x1200
1920x1080x32 (mode 0x17F)

I didn't realize that you hard-coded the resolutions available. Perhaps 1280x960, as it is very uncommon, and replace it with the more-common 1280x1024 which is actually a 5:4 AR. The other 4:3 modes you already have, that is, 640x480,800x600,1024x768. This should take care of most monitors and video cards with 16-bit vBIOSes and VESA. Other exotic resolutions (like 720x480 or 720x576 are rare and less in need of support).

I fixed the zooming bug (hopefully) and I added some more screen resolutions to the list. That did change the command line arguments a little...

https://github.com/SuperIlu/DosView/releases/tag/v1.4

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I just started testing dosview, here some proposals / results:

dosview /? does not show the help but exits with "can`t load image /? ERROR".
So far okay on a real machine. But I noticed that this text is not visible in the small windows of virtual machines.
The exe is so big that I had problems to move it to this real machine with a diskette drive. I had to zip/unzip.
In vmware 17 player with FDT2308 and 32 MB inside I only got a black window when trying "dosview file.jpg" (small picture, slower than 100 k, no idea why) - and there was no chance to come out of the black window, I tried ESC,
STRG-C, ALT-X etc. Upgrading RAM to 1 GB RAM didnt change anything.
With virtualbox I was able to open a 2 MB big jpg - ESC worked, but then there was only a big black screen, no C:\ or something else was visible.
I will try some more vms asap.

But: It works! A great job!

A summary, all versions were tested with dosview 1.4 once again:

Real machine (laptop):
works fine

DOSBOX-X:
I had to upgrade memory first. In dosbox-x.conf "memsize=64" made pictures with a size of 1 MB work. Alternative: Window: Main - Configuration tool - main - memsize - Save.
With 32 MB RAM I got the following error message when trying to open
pictures with a size of more than 1 MB, smaller pictures worked.
Shutting down Allegro
Exiting due to signal SIGSEGV
Page fault at eip=000f61eb
etc. etc.

DOSBox Staging:
path to dosbox-staging.conf is C:\users\username\AppData\Local\DOSBox\dosbox-staging.conf . "memsize=64"
Works as DOSBOX-X

VMWarePlayer 17.5:
FDT2311 installed, I used all 4 boot options (except no driver)
128 MB RAM
Only a black window appears - even if I try to open a 3k jpg file.
I had to kill the machine.

Virtualbox:
FDT2311 installed, I used all 3 boot options (except no driver)
128 MB RAM
dosview opens the pictures (from 3k till 1 MB pictures) - but when pressing
ESC there appears a big black window and I had to kill the machine.

QEmu:

FDT2311 installed, I used all 4 boot options (except no driver):
128 MB RAM
dosview small.jpg does not execute the command at all. It freezes.
After a reboot even dosview -h froze.

> I fixed the zooming bug (hopefully) and I added some more screen
> resolutions to the list. That did change the command line arguments a
> little...
>
> https://github.com/SuperIlu/DosView/releases/tag/v1.4
Thank you. All appears perfect. I'm not seeing any zoom bugs or wrong aspect ratios, especially now that I can display images in my monitor's native resolution of 1920x1080. Do you specifically have any images to test which previously exhibited the AR bug you spoke of?

Thanks for the hint that you are hard-coding of resolutions. I found where in the executable these are hardcoded, and modified some of them to oddball resolutions for my own use (like 720x480, 1024x600, 1366x768, 2048x1536, 1920x1440, etc) that likely won't be useful for anybody else. Every laptop that I have has different VESA resolutions. Video BIOSes have different VESA tables as well... with many strange resolutions beyond the "standard" 4:3 ones.

Until you can automatically detect all VESA resolutions on any given specific machine / vBIOS, and make them available "on the fly" in DOSVIEW, my kludge method of modifying directly the offsets in the DOSVIEW binary works for the outlier oddball resolutions when I need them...

> Until you can automatically detect all VESA resolutions on any given
> specific machine / vBIOS, and make them available "on the fly" in DOSVIEW,
I did some research (again) on how to retrieve a list of available modes from allegro. Last time I only saw an empty list.

Now I know why I failed the first time: The Allegro VESA driver has a bug filtering out text modes which results in returning no modes at all.
I fixed that bug in Allegro and now I'm seeing all modes supported.

Stay tuned for yet another update...

PS: see v1.5 for autodetection.

Also: all my test images are in the GitHub repo

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I was finally able to add VESA mode autodetection. There was a small error in the Allegro library and now ALL* available VESA modes can be selected using "-r"

https://github.com/SuperIlu/DosView/releases/tag/v1.5


(*) Well, all Allegro modes larger than 320x200. I filtered out all the weird stuff below...

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Just a short info:
Qemu now works fine now, but virtualbox and VMWare still have the problems described above. I used the same pictures over all machines.

> Just a short info:
> Qemu now works fine now, but virtualbox and VMWare still have the problems
> described above. I used the same pictures over all machines.
I can check VBox, I don't have VMWare.
So far I have only tested with DOSBox-X and DOSBox-staging. I was to lazy to try my real machines

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Javascript on MS-DOS? Try DOjS https://github.com/SuperIlu/DOjS
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> I can check VBox, I don't have VMWare.
> So far I have only tested with DOSBox-X and DOSBox-staging. I was to lazy
> to try my real machines
VMWarePlayer can be used for free. As the first FD installation is a little bit tricky, here a link to vmsmount, section Examples how to do it:

https://www.bootablecd.de/FreeDOS-Internet-version/help110/en/hhstndrd/util/vmsmount.htm

> I was finally able to add VESA mode autodetection. There was a small error
> in the Allegro library and now ALL* available VESA modes can be selected
> using "-r"
>
> https://github.com/SuperIlu/DosView/releases/tag/v1.5
>
>
> (*) Well, all Allegro modes larger than 320x200. I filtered out all the
> weird stuff below...
Wow, that was fast. In "autodetection" mode, my available modes suddenly went up to 34 on my main laptop. Some of these are really weird (like 360x200 or 640x272) - not all of them work. But, it's great to have the options! Glad you got autodetection working in Allegro.

Incidently, I'm testing only on real bare metal DOS machines. This should be the acid test. Emulators and simulators should be secondary. If they work, all the better...

Sorry... I wrote a wrong post...

From:

https://github.com/SuperIlu/DosView/releases

DosView v1.7

Updated libjpeg to 9f.
Updated libjasper to 4.2.4.
Fixed a crash when running out of memory during loading/display.
Fixed version number when running DosView.
Added key to display help overlay in view mode.
Patched 3rdparty\allegro-4.2.2-xc-master\src\bmp.c to support all BMP formats mentioned in https://en.wikipedia.org/wiki/BMP_file_format#Bitmap_file_header (backport from allegro5).
Fixed DE LSM for FreeDOS.

Thanks for the upgrade! It is wonderful to have an inline help screen now. The program seems more robust and complete.

Sorry... I wrote a wrong message.