markprocessor question

Hi,

mp64 -1 01 ?1?1?1?1?1?1?1?1 -o posibilities.txt

how to make all possibilities but only with 4x 1 and 4x 0 no more in results?

i dont want   11111111 = 8x1
or                 00000000 = 8x0
or 11111000 = 6x1 2x0

i want          11110000 = 4x1 4x0
or                00110011 = 4x1 4x0