The generator matrix

 1  0  0  1  1  1  1  1  1  1  1  1 (a+1)X  1  1  1  1 (a+1)X  1  1  0  1  1  1  1  X  1  X  1  0 aX  X  1  1  1  1  1  1  1  1  1  1 (a+1)X  1  1  1  1  1  1 (a+1)X  1  1 aX  1  1  1  1 aX  1  1  1 aX  1  1  1  1  1  1  0  1  1  1  1  1  1  1  1  1  1 (a+1)X  1  1  1  1 aX  1  1  X  1  1 aX
 0  1  0  0  0 (a+1)X  1 (a+1)X+a a+1 (a+1)X+1  a  a  1 (a+1)X+a (a+1)X+a+1  1 a+1  1 (a+1)X+a+1 (a+1)X+1  1 aX+1 aX+1 aX+a+1 aX+a  1 aX  1 aX+a+1 aX  1  1 aX X+a a+1 X+a+1  a aX+1 aX+a aX (a+1)X+1  1  1 aX+1 X+a (a+1)X+a aX+a a+1  X  1 (a+1)X+a+1  a  1 a+1  1  0 (a+1)X+a+1  1 (a+1)X+a X+a+1  a  1 aX+1 a+1  a  X (a+1)X a+1  1 X+a+1 X+a X+1 X+1  a X+a+1 aX  1  1  0  1 aX+a aX+a+1  0 (a+1)X+1  1 aX+1  X (a+1)X a+1 aX+a (a+1)X
 0  0  1  1  a a+1 X+a+1 a+1 X+a+1  a X+a  0 a+1 X+1  0  1  1  1 X+a  X  a aX+a  X X+a X+1 aX+a+1 X+a+1  1 X+a+1  1  0 aX+a aX+1 (a+1)X aX  1 (a+1)X+a X+1 aX+1 aX+a (a+1)X+a+1 aX  X aX+1 a+1  0 aX+a aX+a aX+a+1 aX+a+1 (a+1)X (a+1)X+a X+a  X a+1  0 X+a X+1 aX+1 a+1 aX+1  a (a+1)X+1 (a+1)X+a+1 aX+a+1 aX+1  X (a+1)X+1  X (a+1)X+1  a a+1  X a+1  a (a+1)X (a+1)X+1 X+a  X aX+a+1 aX+a+1 (a+1)X  X (a+1)X+a+1 aX+a  0 X+a  1  a (a+1)X  1
 0  0  0 (a+1)X  0  0  0  X (a+1)X  X aX (a+1)X  0  0  X aX aX (a+1)X  X aX aX  0 (a+1)X (a+1)X (a+1)X aX (a+1)X (a+1)X  X aX  0 (a+1)X  X (a+1)X  X  0  X  X aX aX aX aX  0  X  0 aX  X aX (a+1)X  0  0 (a+1)X aX  0  0  0 (a+1)X  0 (a+1)X aX  0  X  0  0 aX  0 (a+1)X  X aX aX  0  X aX (a+1)X aX  X (a+1)X aX aX aX  X aX (a+1)X  X aX (a+1)X  0  X (a+1)X  0 aX
 0  0  0  0  X aX aX aX aX  0 (a+1)X  X  0 (a+1)X  X  X  0  X aX (a+1)X  0  0  0 (a+1)X  0 (a+1)X (a+1)X  0  X aX aX (a+1)X  0 (a+1)X (a+1)X  X  0  X  0 aX  0 aX  X aX (a+1)X (a+1)X  X (a+1)X  X aX (a+1)X (a+1)X  X  0  X (a+1)X  0 (a+1)X  X (a+1)X  X  X aX (a+1)X  0 aX  X  0 aX aX  0  0  0  X  X (a+1)X (a+1)X  X  X  X  0  0 aX  X aX aX (a+1)X  0 aX (a+1)X  X

generates a code of length 91 over F4[X,sigma]/(X^2) who´s minimum homogenous weight is 255.

Homogenous weight enumerator: w(x)=1x^0+216x^255+726x^256+240x^257+528x^258+1044x^259+2286x^260+552x^261+1224x^262+2124x^263+3339x^264+720x^265+1932x^266+2880x^267+4122x^268+1032x^269+1968x^270+2856x^271+4848x^272+1044x^273+2076x^274+3216x^275+5223x^276+1008x^277+1944x^278+2844x^279+4038x^280+792x^281+1572x^282+1920x^283+2736x^284+552x^285+768x^286+1032x^287+831x^288+180x^289+228x^290+252x^291+375x^292+24x^293+48x^294+48x^295+69x^296+21x^300+30x^304+6x^308+6x^312+9x^316+6x^324

The gray image is a linear code over GF(4) with n=364, k=8 and d=255.
This code was found by Heurico 1.16 in 30.2 seconds.