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

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

Homogenous weight enumerator: w(x)=1x^0+40x^64+31x^66+4x^67+99x^68+26x^69+80x^70+60x^71+102x^72+96x^73+208x^74+154x^75+601x^76+188x^77+844x^78+160x^79+563x^80+136x^81+207x^82+112x^83+50x^84+58x^85+64x^86+20x^87+48x^88+8x^89+52x^90+2x^91+17x^92+34x^94+14x^96+12x^98+1x^100+1x^102+2x^106+1x^118

The gray image is a code over GF(2) with n=312, k=12 and d=128.
This code was found by Heurico 1.16 in 1.9 seconds.