The generator matrix

 1  0  1  1  1  1  1  1  1  1  1  1  0  1  1  1  1  1  1  1  0  1  1  1  1  1  1  1  1  1  2  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 2a  1  1  1  1  1  1  1  1  1  2  1  1  1  1  1  1  1  1  1  1  1  1  2  1  1  1  1  1  1  1  2  1  1
 0  1  1  a 3a^2+2 2a^2+3a+1 a^2+3a a^2+3a+3 3a^2+2a+3  a 3a^2+2 a^2+3a  1  0 2a^2+3a+1 3a^2+2a+3 2a^2+3 a^2+3a+3 3a^2+2a+3  a  1 a^2+3a  0 3a^2+2 a^2+3a+3 2a^2+3a+3 2a^2+3 3a^2+2a+2  2 2a^2+3a+1  1 2a^2+3a+3 a+2  2 a^2+a a^2+3a+1 3a^2+3 3a^2+2a+2 a^2+a+2 3a 2a^2+3  2 3a^2+1 a^2+a+3 2a^2+2a+3  3 a^2+3a+1 2a 3a^2+2a+2 a^2+a+2 3a^2+2a+1 3a^2+a 3a^2+3a+3 2a^2+1 3a^2+2a+2 2a^2+2a a^2+a+2 a^2+3a+1 2a+3 a^2+2a 3a^2+1 2a^2+2a+1 a+1  1 a^2+2a+2 3a^2+a+2 a^2+3 2a^2+3a a^2+a a^2+3a+1 3a^2+3a+1 a^2+a+1 2a^2+2a+3  1 2a^2+2a+1 a^2+3a+1 2a+3 3a^2+2a+3 2a^2+a+1 3a+2 3a^2+a+3 3a^2+2 a^2+2 2a^2+a+2 a+3 3a^2+3a+3  1 a^2+2a+3 2a^2 2a^2+3a+3 a^2+a+1 2a+3 2a^2+2a+3  0  1 2a^2+3a+1  0
 0  0 2a^2+2  0  2  2 2a+2  2 2a^2 2a+2 2a^2+2 2a^2  2 2a^2+2a 2a^2+2a+2  0 2a^2+2  2 2a^2+2a+2 2a 2a 2a^2+2a 2a+2  2 2a^2+2a+2 2a^2+2 2a^2+2a+2 2a^2+2a+2 2a^2+2a  2 2a^2+2a 2a^2+2a 2a^2+2a 2a^2+2a+2 2a 2a^2+2a+2 2a 2a^2 2a^2  0  0  2  0 2a^2+2a+2 2a+2 2a^2+2a 2a^2+2a  0 2a 2a^2+2a+2  2 2a^2+2 2a+2  0 2a^2+2 2a^2+2a  0 2a^2+2 2a+2 2a^2+2a+2  2  0 2a 2a^2 2a+2 2a 2a 2a^2+2a+2 2a+2  2 2a^2 2a^2+2 2a^2 2a^2+2a 2a^2 2a+2 2a^2  2 2a^2+2a  2  0 2a 2a 2a^2+2a 2a 2a^2  2 2a^2+2a 2a 2a+2 2a^2+2 2a^2 2a 2a^2+2 2a^2+2a+2 2a^2  0
 0  0  0  2 2a^2+2 2a^2+2a+2 2a+2 2a^2 2a^2+2a+2 2a^2+2 2a^2+2 2a^2+2 2a^2+2a+2 2a+2 2a+2 2a^2 2a^2 2a 2a^2  2  0 2a^2+2a 2a  2 2a 2a^2+2a  2 2a^2+2  0 2a 2a^2+2  2 2a+2 2a^2+2a 2a^2+2a  0 2a  2 2a+2 2a^2+2a  2 2a^2+2a+2 2a 2a^2 2a+2 2a^2+2a+2 2a^2+2 2a^2+2 2a^2 2a^2+2a 2a+2 2a^2 2a^2+2a+2 2a^2+2a 2a 2a^2+2a 2a+2 2a^2+2  0 2a 2a^2  0  0  0 2a^2+2a 2a^2 2a^2+2a+2 2a^2+2a+2  2  0 2a^2+2 2a^2+2a+2 2a+2 2a+2 2a^2+2a+2 2a+2  0 2a^2+2a+2  0 2a^2+2 2a  2 2a^2+2a 2a^2+2a+2 2a 2a^2 2a^2 2a 2a+2  2 2a^2+2a  2  2 2a+2 2a^2+2a 2a^2+2 2a^2

generates a code of length 97 over GR(64,4) who´s minimum homogenous weight is 648.

Homogenous weight enumerator: w(x)=1x^0+203x^648+56x^650+280x^653+616x^654+392x^655+749x^656+2072x^657+2408x^658+2744x^661+2912x^662+4200x^663+819x^664+10360x^665+7448x^666+4760x^669+5768x^670+10136x^671+469x^672+16968x^673+11928x^674+7224x^677+6104x^678+22904x^679+434x^680+34216x^681+22736x^682+9072x^685+9520x^686+19712x^687+378x^688+22400x^689+12768x^690+4592x^693+3752x^694+238x^696+231x^704+189x^712+140x^720+91x^728+84x^736+42x^744+21x^752+7x^768

The gray image is a code over GF(8) with n=776, k=6 and d=648.
This code was found by Heurico 1.16 in 25.6 seconds.