Message-Id: <3.0.1.32.19990209100821.0090f100@iut.ujf-grenoble.fr>
X-Sender: sletuffe AT iut DOT ujf-grenoble DOT fr
X-Mailer: Windows Eudora Pro Version 3.0.1 (32) [F]
Date: Tue, 09 Feb 1999 10:08:21 +0100
To: djgpp AT delorie DOT com
From: LETUFFE SYLVAIN <sletuffe AT iut DOT ujf-grenoble DOT fr>
Subject: Problem with video-Banks writing to Dos Memory 
Mime-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Reply-To: djgpp AT delorie DOT com

>Date: Mon, 08 Feb 1999 13:55:30 +0100
>To: djgpp AT delorie DOT com
>From: LETUFFE SYLVAIN <sletuffe AT iut DOT ujf-grenoble DOT fr>
>Subject: Problem with video-Banks writing to Dos Memory 
>In-Reply-To:
<8D53104ECD0CD211AF4000A0C9D60AE34CCD4D AT probe-2 DOT acclaim-euro DOT net>
>
>			
>
>Hy there !
>
>	I am currently writing a programm (with DJGPPP of course !) where I need
to access very 
>quickly to the video memory...(like most of graphical programmers I think)
>
>I don't whant to use Allegro or other libs... I want to do it on my own !!
>
>
>With the 320x200x8 graphical mode I have no problems ( of course there is
only one bank )
>
>But with VESA mode like 101h,125h.. (640x480x8 800x600x8 and higher)
>	I need to bank my memory (previously allocated with malloc() ) with a
fast methode
>The dosmemput() function looks fast enought and I don't think I will need
an acces by out().
>
>BUT,
>
>When I want to bank all my memory the only way (I have) to do this is to
use the 
>
>int 10h (with ax=0x4F05 and bx=0 and dx=bank number)
>
>But it is very slow !!!!
>I fell from 80 fps (13h) (on my DX4) to a pityfull 2 or 3 fps for a
640x480x8 witch is only 5 banks !! 
>
>/*here is my peace of code*/
>
>void dump8(unsigned char *debut, int bankNumber,int BankSize)
>{
>__dpmi_regs registers;
>int i=0;
>while (i<bankNumber)
>      {
>      registers.x.ax=0x4F05;
>      registers.x.bx=0;
>      registers.x.dx=i;
>      __dpmi_int(0x10,&registers);
>      _dosmemputb( debut, BankSize, 0xA0000);
>      debut+=BankSize;
>      i++;
>      }
>}
>
>What can I do to avoid that ??? Could the problem come from something else
than the interuption call ?
>
>												SLY