[fpc-pascal]Graphik with FPC 1.06 DOS Compiler on a 815 Board

Jonas Maebe jonas at zeus.rug.ac.be
Wed Sep 4 23:40:41 CEST 2002

On woensdag, september 4, 2002, at 11:17 , Hans-Joachim Holtzmann wrote:

> I have a problem to draw graphiks on a HP-Vectra with Intel 815 Board 
> (PIII 933MHz) with integrated Graphik. I muist work with NT 4.0 SP6a in 
> a DOS-box
> The test of Graphikmode and Graphikdriver results 3 and 18.
> gm=18 is correct it is a 16 bit graphik with 1024*758 Points.
> gd=3 is wrong because the dokumentation tells me I should get nummbers 
> >30000.

I think you reversed them and that gd=18 and gm=3. gd = 18 means a 16bit 
mode. The gm=3 means simply that that this is the third mode that is 
supported for 16bit color. The return value is only there to be used 
with setgraphmode() later, it's not intended to be used to get any 
useful information (for that purpose, you have GetMaxColor, GetMaxX and 
getMaxY). You should never depend on the values of symbolic constants, 
since they can change at any time.

> If I start Mandel the screen is black and after keypressing the normal 
> text-screen will be back with the message the program needs 3...seconds 
> to create the graphic.

This has nothing to do with the above however.

> The problem is the same with compilerversion 1.04.
> What can I do to fix the problem?

Nothing unfortunately. The video drivers under WindowsNT/2000/XP almost 
always report that they report all these VESA (SVGA) modes, but when you 
actually switch to them, they only draw garbage or nothing). These are 
bugs in the video drivers of your video card (or in WinNT maybe, 
although I've already once heard of someone who was successful) and we 
really cannot do anything about it. Sorry.


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