The generator matrix

 1  0  1  1  1  6  1  1  0  1  1  6  1  1  1  1  2  1  1  1  1
 0  1  3  6  1  1  0  3  1  6  1  1  0  6  3  5  0  0  0  0  0
 0  0  4  0  0  0  0  0  0  0  0  0  4  4  0  4  0  4  4  4  4
 0  0  0  4  0  0  0  0  0  0  0  0  4  0  0  0  4  4  4  0  4
 0  0  0  0  4  0  0  0  0  0  0  0  4  4  0  4  4  0  0  0  4
 0  0  0  0  0  4  0  0  0  0  0  0  4  4  4  4  0  0  4  0  0
 0  0  0  0  0  0  4  0  0  0  0  4  0  4  4  4  0  4  0  0  0
 0  0  0  0  0  0  0  4  0  0  0  4  0  0  0  4  0  4  4  4  0
 0  0  0  0  0  0  0  0  4  0  0  4  0  0  0  0  4  0  4  4  4
 0  0  0  0  0  0  0  0  0  4  0  4  0  4  0  0  4  4  0  4  0
 0  0  0  0  0  0  0  0  0  0  4  0  4  4  4  0  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+146x^12+16x^13+60x^14+128x^15+794x^16+704x^17+1856x^18+3968x^19+5502x^20+6752x^21+4824x^22+3968x^23+2456x^24+704x^25+416x^26+128x^27+270x^28+16x^29+12x^30+45x^32+2x^36

The gray image is a code over GF(2) with n=84, k=15 and d=24.
This code was found by Heurico 1.16 in 4.02 seconds.