The generator matrix

 1  1  1  1  1  1  1  1  1  1  1  1  1  1  1
 0  2  0  0  0  2  2  2 2a  0  2 2a 2a 2a 2a
 0  0  2  0  0 2a^2+2 2a^2+2a+2 2a^2+2a 2a^2+2a  2 2a+2 2a^2+2  0  2 2a^2+2a+2
 0  0  0  2  0  2 2a^2+2a+2 2a 2a+2 2a^2 2a^2+2  0 2a^2+2a+2  2 2a
 0  0  0  0  2 2a^2+2 2a+2 2a 2a^2+2a+2 2a 2a^2 2a^2 2a+2  0 2a

generates a code of length 15 over GR(64,4) who´s minimum homogenous weight is 80.

Homogenous weight enumerator: w(x)=1x^0+1386x^80+2625x^88+4305x^96+11130x^104+229376x^105+8820x^112+4501x^120

The gray image is a code over GF(8) with n=120, k=6 and d=80.
This code was found by Heurico 1.16 in 5.23 seconds.