The generator matrix

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

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

Homogenous weight enumerator: w(x)=1x^0+60x^12+276x^14+354x^16+336x^18+840x^20+4096x^21+1176x^22+616x^24+144x^26+156x^28+116x^30+21x^32

The gray image is a code over GF(2) with n=84, k=13 and d=24.
This code was found by Heurico 1.16 in 0.42 seconds.