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  X  X  X  X  X  X  1  X  X  1  1  1  1
 0  X  0  X a*X a*X a^5*X a^5*X a^6*X a^6*X  0  X a*X a^2*X a^5*X a^2*X  0 a^2*X a^6*X  X a^6*X a*X a^2*X a^5*X a^4*X a^4*X a^4*X a^4*X  0  X a*X  0  X a*X a^2*X a^4*X a^5*X a^6*X a^2*X a^5*X  X a^4*X a^6*X  0 a*X a^2*X a^4*X a^5*X a^6*X  0  X a*X a^2*X a^4*X a^5*X a^6*X a^3*X a^3*X a^3*X a^3*X a^3*X a^3*X a^3*X a^3*X  0  0  X  X  X a*X a*X a^3*X a^3*X  X  0 a^6*X a*X a*X a^2*X a^2*X
 0  0  X a^6*X a^2*X a^4*X  X a^2*X a^6*X a^4*X a*X a^4*X a*X a*X a^3*X a^3*X a^3*X a^6*X a*X a^3*X  X  0 a^2*X a^4*X a^6*X a^2*X  X  0 a^2*X a*X a^6*X a^4*X  X a^3*X a^5*X a^5*X a^5*X a^5*X a^4*X  0 a^5*X a*X a^2*X a^5*X  X  0 a^4*X a^6*X a^3*X a^6*X a^2*X a^5*X  X a^3*X a*X  0  0  X a*X a^2*X a^3*X a^4*X a^5*X a^6*X  0  X a^6*X a^5*X a^4*X  0 a*X a^4*X a^6*X a^2*X a^6*X a^5*X a*X a^3*X  X  0

generates a code of length 80 over F8[X]/(X^2) who´s minimum homogenous weight is 552.

Homogenous weight enumerator: w(x)=1x^0+1736x^552+588x^560+1736x^568+35x^576

The gray image is a linear code over GF(8) with n=640, k=4 and d=552.
This code was found by Heurico 1.16 in 15.3 seconds.