Оформил: DeeCo
Автор: http://www.swissdelphicenter.ch

function SupportsMMX: Boolean;
 begin
   Result := False;
   try
     asm
       push     eax
       push     ebx
       push     ecx
       push     edx
       pushfd
       pop      eax
       mov      ebx,eax
       xor      eax,$00200000
       push     eax
       popfd
       pushfd
       pop      eax
       xor      eax,ebx
       je       @NoMMX
       mov      eax,$01
       test     edx,$800000
       jz       @NoMMX
       mov byte ptr[Result],1

   @NoMMX:
       pop      edx
       pop      ecx
       pop      ebx
       pop      eax
  end;
   except;
   end;
 end;

 procedure TForm1.Button1Click(Sender: TObject);
 begin
   if SupportsMMX then ShowMessage('Computer supports MMX');
 end;