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

generates a code of length 97 over GR(64,4) who´s minimum homogenous weight is 660.

Homogenous weight enumerator: w(x)=1x^0+5824x^660+5824x^661+168x^662+728x^663+2142x^664+2184x^665+6048x^666+784x^667+19880x^668+14000x^669+672x^670+3864x^671+5677x^672+5096x^673+10696x^674+1120x^675+27216x^676+15624x^677+1288x^678+4424x^679+7175x^680+5656x^681+9744x^682+784x^683+25704x^684+16352x^685+1456x^686+5320x^687+6902x^688+4984x^689+9352x^690+896x^691+21728x^692+12712x^693+35x^696+42x^704+28x^712+7x^720+7x^736

The gray image is a code over GF(8) with n=776, k=6 and d=660.
This code was found by Heurico 1.16 in 28.2 seconds.