{ Restores screen to the original state }
function Driver_Restore_Mode: boolean;
begin
asm
mov ax, $0003
int $10
end;
Driver_Restore_Mode := True;
end;
function Driver_Set_Graphics( mode : Int ) : boolean;
var
rc : Int;
begin
Driver_Set_Graphics := False;
rc := 0;
case Mode of
Graphics_Mode_Mono : begin
asm
mov ax, $0012
int $10
end;
Vio_ScanLineWidth := 80;
Vio_Width := 640;
Vio_Height := 480;
end;
Graphics_Mode_Gray : begin
asm
mov ax, $0013
int $10
end;
Vio_ScanLineWidth := 320;
Vio_Width := 320;
Vio_Height := 200;
(* default gray palette takes the gray levels *)
(* the standard VGA 256 colors mode *)
gray_palette[0] := 0;
gray_palette[1] := 23;
gray_palette[2] := 27;
gray_palette[3] := 29;
gray_palette[4] := 31;
end;
else
rc := -1;
end;
if rc <> 0 then exit;
Vio := @Mem[$A000:0];
Driver_Set_Graphics := True;
end;
procedure Driver_Display_Bitmap; assembler;
asm
push ds
push bp
les di, [Vio]
cld
mov cx,[Vio_ScanLineWidth]
mov bx,[col]
mov ax,[line]
dec ax
mul cx
add di,ax
mov dx,[line]
lds si,[Buff]
mov bp,bx
add bx,cx
@1:
mov cx,bp
rep movsb
sub di,bx
dec dx
jnz @1
pop bp
pop ds
end;