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

generates a code of length 78 over Z8 who´s minimum homogenous weight is 64.

Homogenous weight enumerator: w(x)=1x^0+79x^64+108x^65+229x^66+358x^67+439x^68+522x^69+752x^70+848x^71+1075x^72+1490x^73+1678x^74+2182x^75+2518x^76+2662x^77+2863x^78+2614x^79+2528x^80+2228x^81+1766x^82+1618x^83+1045x^84+918x^85+669x^86+444x^87+374x^88+218x^89+190x^90+114x^91+108x^92+42x^93+33x^94+14x^95+22x^96+4x^97+9x^98+2x^100+3x^102+1x^120

The gray image is a code over GF(2) with n=312, k=15 and d=128.
This code was found by Heurico 1.16 in 80.2 seconds.