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  X  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1
 0  X  0  0  0  0  0  X  X 4X 2X 3X 4X 3X 3X 3X 2X 2X  0  0 2X 2X 3X 3X 2X 2X 2X  0  0 2X 3X 4X 3X  0 3X 2X 3X 4X 4X 2X  X 4X  0 4X 4X 4X  0 4X 2X  X 4X 3X 4X  X  X  0 2X 3X  0 2X  0 4X 3X 3X  X 4X 3X 4X  0
 0  0  X  0  0  X  X 3X 4X 3X  0  X 2X 2X 4X  0 4X  X  X  0  X 3X  X 3X 4X  0 2X 2X 2X  X 4X 4X  X 3X 3X 4X 2X 4X  X  0  X  0  0  0  X  0 2X  0 2X  X  0 2X 2X  X 3X 4X 2X 2X  0 4X  X 3X  X 3X  0 2X 2X 3X 3X
 0  0  0  X  0 3X 2X 3X  X  X 4X  X  0  X 2X  X  X 2X 3X 2X  X  0  X 4X 3X 2X 4X 2X 3X 2X 2X 4X  0 3X 2X  0 2X 3X  X  X  0 4X 4X  0 3X 4X  X  X  X 3X 3X 4X 4X  X 4X  X 3X 3X  X 2X 2X  0 3X 2X 4X 2X 2X 3X 2X
 0  0  0  0  X 3X  X 4X 3X  X 3X 4X 2X  0  0  X  0 3X 2X  X  X 4X  X 2X  0 4X  0 4X  X 4X  X 2X 4X 2X 3X 2X 4X 3X 3X 4X 4X 4X 4X  X  X  0 4X  X  0 2X  0 4X  0 2X 4X  0  X 2X 2X 3X 2X  X 4X 4X 3X 2X 2X 4X 3X

generates a code of length 69 over Z5[X]/(X^2) who´s minimum homogenous weight is 255.

Homogenous weight enumerator: w(x)=1x^0+272x^255+412x^260+472x^265+388x^270+2500x^272+328x^275+10000x^277+280x^280+256x^285+204x^290+136x^295+128x^300+108x^305+72x^310+40x^315+16x^320+8x^325+4x^340

The gray image is a linear code over GF(5) with n=345, k=6 and d=255.
This code was found by Heurico 1.16 in 6.12 seconds.