The generator matrix

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

generates a code of length 21 over Z8 who´s minimum homogenous weight is 12.

Homogenous weight enumerator: w(x)=1x^0+28x^12+4x^13+116x^14+32x^15+134x^16+112x^17+52x^18+224x^19+88x^20+2328x^21+232x^22+224x^23+224x^24+112x^25+72x^26+32x^27+12x^28+4x^29+36x^30+25x^32+4x^34

The gray image is a code over GF(2) with n=84, k=12 and d=24.
This code was found by Heurico 1.16 in 0.115 seconds.