The generator matrix

 1  0  1  1  1  0  1  1  X  1  1  X  1  1  0  1  1  0  1  1  1  1  X  X  X  X  0  0  1  1  1  1  0  X  X  X  0  1  1  1  1  0
 0  1  1  0 X+1  1  X X+1  1  X  1  1  0 X+1  1  0 X+1  1  X  X  1  1  1  1  0  X  X  0  0  X X+1  1  1  1  0  X  X  0 X+1  X  1  1
 0  0  X  X  0  X  X  X  X  0  0  0  0  0  X  X  X  0  X  0  X  0  X  0  X  X  X  X  0  0  0  0  X  X  0  0  0  X  X  X  X  0

generates a code of length 42 over Z2[X]/(X^2) who´s minimum homogenous weight is 42.

Homogenous weight enumerator: w(x)=1x^0+6x^42+16x^43+6x^44+2x^46+1x^48

The gray image is a linear code over GF(2) with n=84, k=5 and d=42.
As d=42 is an upper bound for linear (84,5,2)-codes, this code is optimal over Z2[X]/(X^2) for dimension 5.
This code was found by Heurico 1.16 in 0.00791 seconds.