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

generates a code of length 96 over GR(64,4) who´s minimum homogenous weight is 664.

Homogenous weight enumerator: w(x)=1x^0+196x^664+3836x^672+28x^696+28x^704+7x^768

The gray image is a code over GF(8) with n=768, k=4 and d=664.
This code was found by Heurico 1.16 in 0.159 seconds.