byte 2 bin byte array

var
  a: byte;
  MASK: byte;
  arr : Array[0..7] of byte;
  iindex : byte;
begin
  a:= random($ff);
  MASK := ($80-1);// ($1 shl (sizeof(a)*7) )-1
  //writeln(MASK);
  write('a= ');
  write(a);
  write('= ');
  write(a div 16 );
  write(',');
  write(a mod 16 );
  writeLn('');

//msb 1 byte  to 8byte
  for iindex := 7 downto 0 do
  begin
    if a > MASK then arr[iindex]:=1 else arr[iindex]:=0;
    a:= a shl 1;
    write(arr[iindex]);
  end;
  //writeLn('-----------');