DOS 5.0 Graphical glitches upon exiting DOSSHELL

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T4nkcommander
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DOS 5.0 Graphical glitches upon exiting DOSSHELL

Post by T4nkcommander »

See title. Every time I try to exit from DOSSHELL I get unreadable text. Due to the....strange...nature of the DOS machine I'm trying to virtualize, I often can't open files except through the DOSSHELL. Here's a pic of me trying to open a txt file:
Graphical issues
Graphical issues
Untitled.png (112.94 KiB) Viewed 9966 times
3D accel is not selected, and I'm using VBoxVGA with 9mb of video memory. Any ideas? Thanks in advance.

Also, if anyone has any tips for solving QEMM386 not properly allocating space - despite being assigned 512mb by Vbox - I'd love your input.
mpack
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Re: DOS 5.0 Graphical glitches upon exiting DOSSHELL

Post by mpack »

Does the DOSSHELL version you have use a a graphical mode when running? Because it looks to me like something has reprogrammed the fonts.

Also, 9MB sounds low for graphics RAM. I'd put it back to 16MB, which I believe was the template default.
T4nkcommander
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Re: DOS 5.0 Graphical glitches upon exiting DOSSHELL

Post by T4nkcommander »

I dont know about the answer to your first question, but the second is easy. That's what Vbox defaulted to and I assumed that was a good value.

I just upped the value but the issue persists. I'm inclined to think what you are saying about the font changing is true, but as this OS is as old as me I only learned about DOSSHELL yesterday.
mpack
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Re: DOS 5.0 Graphical glitches upon exiting DOSSHELL

Post by mpack »

T4nkcommander wrote:the second is easy. That's what Vbox defaulted to and I assumed that was a good value.
What template did you select? Because when I select "DOS", graphics RAM defaults to 16MB as I said above.

You didn't answer my question: does the DOSSHELL app that you're using switch to a graphical mode? It should be quite obvious: no gaps between text cells, smooth cursor movement (actually that may be harder to spot in a VM, and the fact that the resolution matches a known vga graphics mode). I never used it myself, but I've done some research and ISTM that the DOSSHELL was around for a long time, and a graphical mode might have been an option on some releases. Primarily however it seems to have been a text mode app: but I guess it still could have played with fonts.

My point being, that it may be making assumptions about the BIOS that are not correct.
fth0
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Re: DOS 5.0 Graphical glitches upon exiting DOSSHELL

Post by fth0 »

mpack wrote:What template did you select? Because when I select "DOS", graphics RAM defaults to 16MB as I said above.
Are you using a WQHD (2560x1440) display? ;)

The "DOS" template really has 4 MB, but VirtualBox calculates the minimum amount that is needed when using the largest available display fullscreen and enforces the maximum of those two values as a minimum. The OP probably uses a full HD display (1920x1080).
T4nkcommander
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Re: DOS 5.0 Graphical glitches upon exiting DOSSHELL

Post by T4nkcommander »

I actually am using 4K, but the behavior is not specific to just DOSSHELL. It does appear to be related to most anything that swaps to a different 'mode' while running - Quarterdeck QSETUP and FDISK give issues, although interestingly MFT does not.

I noticed disabling QEMM386 seemed to solve it, which is unfortunate as it is critical to this machine.
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