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#556 Pixel pannin mode bug on VGA text mode
open
nobody
1
2022-02-23
2022-02-19
No
I was testing some vga registers on dosbox 0.74-3, and I noticed a bug.
Setting 8 pixel wide cells in text mode, disables pixel panning functions (03c0 index 13). This allows text mode to move right or left by one pixel.
This works on real machines, (also on some SVN Dosbox distributions, and other pc emulators like pcem).
I attach a little program to test this.
Run "pan" to leave cells with 9 pixels wide, or write any parameter "pan 1" to set cells to 8 pixels wide.
Reading my post I don't know if it is clear what I wanted to report :(.
Set 8 pixel wide cells in text mode (test "pan.exe 1"):
- Dosbox 0.74-3 => smooth scroll stops working.
- Real machine => smooth scroll works.
Leave text cells with default 9 pixels wide (test "pan.exe"):
- Dosbox 0.74-3 => smooth scroll works.
- Real machine => smooth scroll works.
Have you tried a build of current source with the machine=vgaonly setting?
Yes, that's the first thing I tested
In your report you only mention DOSBox 0.74-3, and that is not current source. SVN is current source.
I'm sorry, I think I don't understand very well what you said. Where do I download SVN? . I can only find downloads for 0.74-3.
I tested libretro dosbox core, it looks like that is using the last svn sources, and it has the same bug. EDIT: it looks like it is solved there :)
Last edit: David Gila Blázquez 2022-02-23