The generator matrix

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

generates a code of length 94 over GR(64,4) who´s minimum homogenous weight is 639.

Homogenous weight enumerator: w(x)=1x^0+6216x^639+4977x^640+280x^641+672x^642+1232x^643+4704x^644+3472x^645+2632x^646+19880x^647+12229x^648+1400x^649+3864x^650+2352x^651+7896x^652+6552x^653+4592x^654+28112x^655+14189x^656+2632x^657+4592x^658+3696x^659+10416x^660+6048x^661+4424x^662+28168x^663+16450x^664+2856x^665+5208x^666+3472x^667+9240x^668+5432x^669+2688x^670+21560x^671+9919x^672+21x^680+28x^688+14x^696+7x^704+14x^712+7x^720

The gray image is a code over GF(8) with n=752, k=6 and d=639.
This code was found by Heurico 1.16 in 20.7 seconds.