The generator matrix

 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  1  2  1  2  2  2  1  2  4  1  2  4  1  2  1  1  1  2  2  1  4  1  0  1  2  1  2  4  1  1  1  1  2  1  4  0  4  1  2  1  4  1  2  2  1  4  1  1
 0 12  0  4  0  0  4 12  0  0 12 12  0  8 12  8 12  0  4 12 12  0  8  4  8  8 12 12  4  0 12  4  8  8  4  0  4  4 12 12 12  0  0  8 12  8  0 12  0  8 12  4  4  0  8  4  0  4  4  8  4  8  8  8 12  8 12  8  4  8  4  0  4  8 12  4 12 12  4  0
 0  0 12  4  0 12  4  0  0 12 12  8  8 12  4  4  0  8  4  0  4  4  8  4  4  8  0  0  0 12 12  4 12  4 12 12  4  4  8  8  8  8 12  4 12  4 12 12  0  4  8  0 12  0  4  4 12  8 12  4  4  0  4  8  4  0  0  4  4  4 12  4  4  0  8  8  8  0  4  0
 0  0  0  8  0  0  0  0  0  0  0  0  0  0  8  0  0  0  0  8  0  8  8  8  8  8  0  0  0  8  0  8  8  8  0  8  0  0  0  8  8  0  8  0  8  8  8  0  8  8  8  0  8  0  8  8  0  0  0  0  0  8  0  0  0  0  8  8  8  8  8  0  8  0  8  8  0  0  8  0
 0  0  0  0  8  0  0  0  0  0  0  8  0  0  8  8  8  8  0  8  8  0  8  8  0  8  0  8  8  0  8  0  8  0  8  0  0  8  0  0  8  8  0  0  8  0  8  0  0  0  8  0  0  8  0  8  8  8  0  0  8  0  0  0  0  0  0  8  8  8  0  0  8  8  0  0  8  8  0  0
 0  0  0  0  0  8  0  0  0  0  0  0  0  8  0  0  8  8  0  8  0  8  8  0  8  8  0  0  8  0  0  0  8  0  8  8  8  0  8  8  0  8  0  8  0  8  0  0  0  0  8  0  0  8  8  8  0  8  0  0  8  8  0  8  0  8  0  8  0  0  0  8  8  8  8  8  8  8  8  0
 0  0  0  0  0  0  8  0  0  0  8  0  0  0  0  0  0  0  8  8  8  8  8  0  8  8  0  0  0  8  8  0  8  0  8  0  8  8  0  8  8  0  8  0  8  0  0  0  0  8  0  8  8  8  8  8  8  8  0  0  0  0  8  8  8  8  0  0  0  0  8  8  0  0  0  8  8  8  8  0
 0  0  0  0  0  0  0  8  0  0  8  0  8  8  0  0  0  8  8  8  0  0  8  8  0  0  0  8  8  8  0  0  8  0  0  0  8  0  0  0  8  0  8  0  8  8  8  8  0  8  8  0  0  0  8  0  8  8  8  8  8  8  0  8  8  8  8  8  0  0  8  8  0  8  0  0  8  0  8  0
 0  0  0  0  0  0  0  0  8  0  0  0  8  0  0  0  0  0  0  0  0  0  0  0  0  8  8  8  8  8  8  8  8  0  8  8  0  8  8  0  8  8  0  8  0  0  0  8  8  8  8  0  0  0  0  0  8  8  8  8  8  8  0  0  0  8  8  8  0  8  0  8  8  8  8  8  0  0  8  0
 0  0  0  0  0  0  0  0  0  8  0  0  0  0  0  8  0  0  8  0  8  8  8  8  0  8  8  8  8  0  8  8  8  8  0  8  0  0  0  0  0  8  8  8  0  0  8  0  0  0  8  8  8  0  0  0  0  0  8  0  8  0  0  0  8  8  8  0  8  8  8  8  0  0  8  8  8  8  8  0

generates a code of length 80 over Z16 who´s minimum homogenous weight is 66.

Homogenous weight enumerator: w(x)=1x^0+42x^66+28x^67+124x^68+110x^69+248x^70+258x^71+412x^72+458x^73+693x^74+992x^75+1335x^76+2402x^77+3096x^78+3970x^79+4515x^80+3958x^81+3206x^82+2388x^83+1283x^84+986x^85+644x^86+430x^87+358x^88+222x^89+169x^90+112x^91+122x^92+54x^93+69x^94+14x^95+26x^96+2x^97+18x^98+15x^100+6x^102+1x^108+1x^110

The gray image is a code over GF(2) with n=640, k=15 and d=264.
This code was found by Heurico 1.16 in 37.7 seconds.