The generator matrix

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

generates a code of length 64 over F4[X,sigma]/(X^2) who´s minimum homogenous weight is 180.

Homogenous weight enumerator: w(x)=1x^0+486x^180+168x^181+504x^183+1830x^184+696x^185+636x^187+2004x^188+660x^189+612x^191+1965x^192+552x^193+600x^195+1806x^196+492x^197+468x^199+1317x^200+276x^201+144x^203+612x^204+168x^205+96x^207+204x^208+60x^209+12x^211+12x^212+3x^216

The gray image is a linear code over GF(4) with n=256, k=7 and d=180.
This code was found by Heurico 1.16 in 1.15 seconds.