The generator matrix

 1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  2  0  1  0  2  1  1  2  1  0  1  1  1  4  4  1  0  1  1  2  1  2  1  0  1  2  2  2  2  2  2  1
 0  2  0  2  0  0  2  6  0  4  6  2  0  2  2  4  4  0  2  6  0  0  6  6  4  6  2  4  4  2  2  0  0  4  4  2  0  4  6  0  2  0  0  2  4  2  2  4  0  2  6  4  0  2  2  2  2  6  2  4  4  2  2  0
 0  0  2  2  0  6  2  0  4  2  0  2  0  6  4  6  2  0  2  4  6  0  4  2  4  2  4  0  2  6  4  6  6  2  2  0  6  2  4  6  2  2  0  4  6  2  6  6  2  0  2  2  2  6  6  0  4  4  2  2  6  6  0  0
 0  0  0  4  0  0  0  0  4  4  4  0  4  4  4  4  4  0  4  4  4  4  4  4  4  4  0  0  4  4  0  0  4  0  4  4  0  0  4  0  0  4  0  0  0  0  0  0  0  0  4  0  4  0  4  4  0  0  4  0  4  4  0  4
 0  0  0  0  4  0  0  0  0  0  0  4  4  4  0  0  0  0  4  4  4  4  4  0  4  0  4  0  4  4  0  0  0  4  4  0  0  4  4  4  0  4  4  0  4  4  4  0  0  4  0  0  4  0  4  0  4  4  0  4  4  4  4  0
 0  0  0  0  0  4  0  0  0  4  0  4  4  0  4  0  4  0  0  4  4  0  0  0  0  4  4  4  4  0  0  4  0  4  0  0  0  0  4  0  4  4  0  4  4  4  4  0  0  0  4  0  0  4  4  4  0  4  4  4  0  4  0  4
 0  0  0  0  0  0  4  0  4  4  4  4  4  0  4  4  0  4  4  0  4  0  0  4  0  4  4  4  4  4  4  0  4  4  4  4  0  0  4  4  4  4  0  4  0  0  4  4  4  4  0  4  0  4  0  4  0  0  0  4  4  4  4  0
 0  0  0  0  0  0  0  4  0  0  0  4  0  4  4  0  0  4  0  4  0  0  4  0  4  4  0  0  4  4  0  4  4  4  0  4  4  0  0  0  0  4  4  4  4  4  0  0  0  0  0  4  4  0  0  4  0  0  4  4  4  0  4  0

generates a code of length 64 over Z8 who´s minimum homogenous weight is 56.

Homogenous weight enumerator: w(x)=1x^0+205x^56+12x^57+244x^58+104x^59+412x^60+136x^61+510x^62+248x^63+501x^64+272x^65+404x^66+152x^67+350x^68+88x^69+190x^70+8x^71+143x^72+4x^73+46x^74+43x^76+12x^78+6x^80+2x^82+2x^84+1x^92

The gray image is a code over GF(2) with n=256, k=12 and d=112.
This code was found by Heurico 1.16 in 56.3 seconds.