The generator matrix

 1  0  0  1  1  1  0  1  1 X^2  1  X  1  0  1 X^2+X  1  1 X^2+X  1  X  X  1  1 X^2+X X^2  1  1  1  1  0  1  1  0  1 X^2+X  1  1 X^2 X^2+X  1  0  X X^2+X X^2  1  1  1  1  1  0 X^2+X  0  1  1  1 X^2  X  1  1 X^2+X  1  X  1
 0  1  0  0  1  1  1 X^2  1  1 X^2+1  1 X^2+X X^2+X X+1  1 X^2+X+1 X^2+X  X X^2+X  1  1  X X+1 X^2  1  0 X+1  0 X+1 X^2  1 X^2  X X^2+X  1 X^2 X^2+X+1 X^2+X  1 X+1  1  X  1  1  1  1  0 X^2  1 X^2+X  X X^2 X^2 X^2+X+1 X^2+1  1  1 X+1  0  1 X^2+1  0 X^2+X+1
 0  0  1 X+1 X^2+X+1  0 X+1  X  1 X^2+1  X X^2+X X+1  1  X  0  1 X^2  1 X^2+1  1 X^2+X+1 X^2+X X^2  1 X^2+X  1 X+1 X^2 X^2  1 X^2+1  1  1  0 X^2 X^2+X X^2+1  1 X^2  X X^2+X+1  1 X^2+X X^2+X+1 X+1  0 X^2+X+1 X^2+X  0  1  1  1  0  0  0  1 X+1 X^2 X^2+X  X X^2  1  1
 0  0  0 X^2  0  0  0 X^2 X^2 X^2  0  0  0 X^2 X^2 X^2 X^2 X^2  0  0  0 X^2  0 X^2 X^2 X^2 X^2 X^2 X^2  0 X^2  0  0  0  0 X^2 X^2  0  0  0  0  0  0 X^2 X^2  0 X^2 X^2  0 X^2 X^2 X^2 X^2 X^2 X^2  0  0  0  0  0 X^2  0  0  0
 0  0  0  0 X^2  0 X^2  0 X^2 X^2 X^2 X^2  0  0 X^2 X^2  0 X^2 X^2 X^2  0  0 X^2  0 X^2 X^2  0 X^2 X^2 X^2  0 X^2 X^2 X^2 X^2  0  0  0  0  0  0  0  0  0  0  0  0 X^2  0  0 X^2  0 X^2 X^2 X^2 X^2 X^2  0  0  0 X^2  0  0 X^2
 0  0  0  0  0 X^2  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0 X^2 X^2 X^2 X^2 X^2 X^2 X^2 X^2 X^2 X^2 X^2 X^2 X^2  0 X^2 X^2  0 X^2 X^2  0 X^2 X^2  0  0  0 X^2 X^2 X^2 X^2  0 X^2  0  0 X^2 X^2 X^2  0  0 X^2  0

generates a code of length 64 over Z2[X]/(X^3) who´s minimum homogenous weight is 58.

Homogenous weight enumerator: w(x)=1x^0+256x^58+720x^60+878x^62+817x^64+562x^66+383x^68+268x^70+110x^72+76x^74+16x^76+6x^78+2x^82+1x^84

The gray image is a linear code over GF(2) with n=256, k=12 and d=116.
This code was found by Heurico 1.16 in 1 seconds.