ems.h

c游戏编程从入门到精通_全部源代码和文档

#ifndef TOTEM_EMS

#define TOTEM_EMS

char EMS=0;

char test_ems()
{ int i;
  union REGS inregs,outregs;
  struct SREGS segs;
  struct DeviceHeader {
    struct DeviceHeader far *link;
    unsigned attributes;
    unsigned strategy_offset;
    unsigned interrupt_offset;
    char name_of_number_of_units[8];
  } far *dev;
  unsigned char major,minor,c[13];
  inregs.x.ax=0x3001;
  intdos(&inregs,&outregs);
  major=outregs.h.al;
  minor=outregs.h.ah;
  if (major<2) return(0);
  else
  {
     inregs.h.ah=0x52;
     intdosx(&inregs,&outregs,&segs);
     if (major==2)
       dev=(struct DeviceHeader far *)MK_FP(segs.es+1,outregs.x.bx+7);
     else
       if ((major==3) && (minor==0))
	 dev=(struct DeviceHeader far *)MK_FP(segs.es+2,outregs.x.bx+8);
       else
	 dev=(struct DeviceHeader far *)MK_FP(segs.es+2,outregs.x.bx+2);
     c[8]=NULL;
     while (FP_OFF(dev)!=0xffff)
     {
       if (dev->attributes & 0x8000)
       {
	 for (i=0;i<8;i++)
	   c[i]=dev->name_of_number_of_units[i];
       }
       if (!strcmp(c,"EMMXXXX0"))
       {
	 EMS=1;
	 return(1);
       }
       dev=dev->link;
     }
  }
  return(0);
}

char get_EMS_status()
{
  char tmp=0xff;
  if (EMS)
  {
    asm {
      mov ah,0x40
      int 0x67
      mov tmp,ah
    }
  }
  return(tmp);
  }

char get_page_frame_segment(unsigned *segment)
{
  char tmp=0xff;
  if (EMS)
  {
    asm {
      mov ah,0x41
      int 0x67
      mov tmp,ah
    }
    *segment=_BX;
  }
  return(tmp);
}

char get_number_of_pages(unsigned *avail,unsigned *total)
{
  char tmp=0xff;
  if (EMS)
  {
    asm {
      mov ah,0x42
      int 0x67
      mov tmp,ah
    }
   *avail=_BX;
    *total=_DX;
  }
  return(tmp);
}

char allocate_memory(unsigned *handle,unsigned page_numbers)
{
  char tmp=0xff;
  if (EMS)
  {
    asm {
      mov ah,0x43
      mov bx,page_numbers
      int 0x67
      mov tmp,ah
    }
    *handle=_DX;
  }
  return(tmp);
}

char map_memory(char physical_page,unsigned logical_page,unsigned handle)
{
  char tmp=0xff;
  if (EMS)
  {
    asm {
      mov ah,0x44
      mov al,physical_page
      mov bx,logical_page
      mov dx,handle
      int 0x67
      mov tmp,ah
    }
  }
  return(tmp);
}

char release_memory(unsigned handle)
{
  char tmp=0xff;
  if (EMS)
  {
    asm {
      mov ah,0x45
      mov dx,handle
      int 0x67
      mov tmp,ah
    }
  }
  return(tmp);
}

char get_EMM_version(unsigned char *version)
{
  char tmp=0xff;
  if (EMS)
  {
    asm {
      mov ah,0x46
      int 0x67
      mov tmp,ah
    }
    *version=_AL;
  }
  return(tmp);
}

char save_mapping_context(unsigned handle)
{
  char tmp=0xff;
  if (EMS)
  {
    asm {
      mov ah,0x47
      mov dx,handle
      int 0x67
      mov tmp,ah
    }
  }
  return(tmp);
}

char restore_mapping_context(unsigned handle)
{
  char tmp=0xff;
  if (EMS)
  {
    asm {
      mov ah,0x48
      mov dx,handle
      int 0x67
      mov tmp,ah
    }
  }
  return(tmp);
}

char get_number_of_EMM_handles(unsigned *handle_numbers)
{
  char tmp=0xff;
  if (EMS)
  {
    asm {
      mov ah,0x4b
      int 0x67
      mov tmp,ah
    }
    *handle_numbers=_BX;
  }
  return(tmp);
}

char get_pages_owned_by_handle(unsigned handle,unsigned *page_numbers)
{
  char tmp=0xff;
  if (EMS)
  {
    asm {
      mov ah,0x4c
      mov dx,handle
      int 0x67
      mov tmp,ah
    }
    *page_numbers=_BX;
  }
  return(tmp);
}

char get_pages_for_all_handles(unsigned char *buffer,unsigned *handle_numbers)
{
  char tmp=0xff;
  if (EMS)
  {
    unsigned bseg=FP_SEG(buffer),boff=FP_OFF(buffer);
    asm {
      mov ah,0x4d
      mov di,boff
      mov es,bseg
      int 0x67
      mov tmp,ah
    }
    *handle_numbers=_BX;
  }
  return(tmp);
}

#endif