silsor wrote:

For some reason the VGA emulation doesn't work properly for the old Nahlakh RPG. I posted details on this at http://dosbox.sourceforge.net/comp_list.php?showID=1888 . Does anybody have an idea why text stays on the screen after it's supposed to be cleared or why the colours get all messed up? Maybe it's a mode switching improperly?

Have you tried to adjust the "machine" parameter in the config file? the "auto" setting doesn't always work correctly. Try setting it to "vga" or"cga". Some games (notably older Sierra AGI games) autodetect Tandy, but then go ahead using EGA, causing similar problems.

JAL

Changing the machine option doesn't help. With VGA the game has the same graphics errors, and with CGA it correctly refuses to run (it's a VGA game). Other than these graphics errors the game seems to run perfectly.

I took some screenshots:

This is the opening screen. It works fine. The game cycles the palette during this screen to create the illusion of shifting red clouds.

This is the load game screen that appears next. As you can see the palette has been reset to the standard VGA 256-colour palette but the intro screen has not been erased.

This is the in-game screen. Nothing has been erased yet, everything is being drawn on top.

This is a character's inventory. It too is drawn on top of everything else.

Edit: I also tried it with CVS dosbox, same problem.

Something that comes up in the debugger a lot:

INT10:Unhandled mode 6 for scroll
(about 20 times)

I don't know if this pertains to graphics.

do those messages in the debug screen happen at the same time or at moment the screen should be emptied ?

if you scroll a window enough the window get's empty. Might be some behaviour this game is relying on...

The error messages happen at the same time the screen should be blanking. I can't tell if there are the same number of errors as there are lines on the screen, because there seems to be no way to scroll up in the debugger.

ah okay This is the problem:

I think it uses the scroll functions to clear the screen
We didn't implement scrolling in VGA as nobody seemed to use it.

Oh well here's one that uses it 😀

Seems like a pretty silly way to clear the screen. Can I hope for a fix for this sometime? I'm not stalking you, I just happened to be fixing the screenshots at the same time you replied ;)

maybe/probably.
But as only one games seems to use it at the moment it isn't given a very high priority.

Using scrolling the clear the screen is quite common in text mode though. for VGA it's indeed a bit strange.

Not just one ...
There is probably similar problem in those Ultima 2 and 3 VGA updates:

ultima 2 and 3

141133809: INT10:Unhandled mode 6 for scroll
141133809: INT10:Unhandled mode 6 for scroll
....

Mirek

hmm it's not that hard to implement.
Oh well let's see if I can find those games.

The scrolling problem is fixed now in CVS, thank you for writing that function. There is one minor graphics issue left:

In this screenshot the text should be visible, but the skill names seem to be printed on a background of the same colour. The ratings look mostly okay, I don't have access to real DOS right now so I can't tell if the ones with the background colours are supposed to have them.

Hmm yes annoying, was kinda wondering when this was gonna happen since in mode 0x13 you can't xor characters on the screen using bit 7, but bit 7 is just part of the color 😀

Edit:

Okay that fixed now too i think.