size% = 256

      VDU 23,22,size%;size%;8,8,16,0
      OFF

      DIM coltab%(size%-1)
      FOR I% = 0 TO size%-1
        coltab%(I%) = ((I% AND &FF) * &010101) EOR &FF0000
      NEXT

      GCOL 1
      FOR I% = 0 TO size%-1
        FOR J% = 0 TO size%-1
          C% = coltab%(I% EOR J%)
          COLOUR 1, C%, C%>>8, C%>>16
          PLOT I%*2, J%*2
        NEXT
      NEXT I%

      REPEAT WAIT 1 : UNTIL FALSE