Thread: No acess to the video memory????

Only for mode 0x13h which is 320x200 8-bit. EGA and some CGA are mapped to B800:0000

Not realy Bubba , all graphic modes, in mcga,ega vga are in 0xa000:0000
0xB800 is to text modes only

Now... i have tested some other colors, and i dont see the light.

do not worry this is only an exercise


and if I could take this function of my brain, not copy & paste
for mode 0x12 680x480x16 planar mode,
I also get there in mode 0x101,later

Code:

/*
								*** vbeMemCpy(...) ***
	 copy pixels one by one to all four planes

	first to call this function
	you may set
		far Pointer to destination memory          *dst
		 reserv buf where store the image       *src
		 Set WriteMode  to 3
		 MapMask Register  to all four planes   outpw(0x3c4,0x0f02)
		 BitMapRegister   to all 8 bits         outpw(0x3ce,0xff08)
		 set index reg to SetReset register     outp(0x3ce ,0)
	now
		SetReset define de color                outp(0x3f,*src++)
		and cpu data define the index pixel     *dst=i
*/
void vbeMemCpy(unsigned char far*src,unsigned char far*dst,unsigned int x,unsigned x1,unsigned int len){
	  unsigned char tmp;
	  unsigned char i,i1;
	  i=(0x80>>(x1&0x07));            // i= what pixel in the first 8 dst pixels?
	  i1=x&0x01;                             //  i1=what pixel in the first 2  src pixels
	  if(i1)tmp=*src&0x0f;else tmp=*src>>4;
	  while(len--){
			 outp(0x3cf,tmp);     //SetReset    set color
			 tmp=*dst;              // upload the latches
			 *dst=i;                   //set this bit in all 4 planes
			 i=(i>>1);                // next pixel
			 i1++;
			 if(i==0){ i=0x80;dst++; }
			 if(i1&0x01)tmp=*src&0x0f;else{ src++;tmp=*src>>4;}
	  }

}

you cannot use the LFB without a DOS extender

Just out of curiosity, Bubba, what do you mean by that? I've never heard the term "DOS extender" before.

Do you just mean that you need a compiler that can compile to DOS?

Every once in awhile I open up my old 13h graphics programs and recompile them and run them. I do it under Borland C++ 5.02 which is the IDE I developed them all on, and it compiles to DOS. I haven't tried doing it with Visual Studio or gcc...but I should try. I would need to change all the assembly code (which isn't that much honestly) to be in gcc's assembly format rather than Borland's.