Частота

function SetScreen(BPP: byte; Width, Height, FRate: integer): boolean;
var
  D: TDevMode;
  h: hWnd;
begin
  h:=0;
  d.dmDeviceName:='DISPLAY';
  d.dmBitsPerPel:=bpp;
  d.dmDisplayFrequency:=FRate;
  d.dmPelsWidth:=width;
  d.dmPelsHeight:=height;
  d.dmFields:=DM_BITSPERPEL+DM_PELSWIDTH+DM_PELSHEIGHT+DM_DISPLAYFREQUENCY;
  d.dmSize:=SizeOf(D);
  result:=false;
  if ChangeDisplaySettings(D,CDS_TEST)=DISP_CHANGE_SUCCESSFUL then
  begin
    ChangeDisplaySettings(D,CDS_UPDATEREGISTRY);
    result:=true;
  end;
end;