Here is how to do it with a few lines of bash:

  function matrix () {
      echo -e "\e[1;40m"
      clear
      while :; do
          echo $LINES $COLUMNS $(( $RANDOM % $COLUMNS)) $(( $RANDOM % 72 ))
          sleep 0.05
      done|awk '{
          letters="abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789あいうえおかきくけこさしすせそたちつてとなにぬねのはひふへほまみむめもやゆよらりるれろわをん@#$%^&*()";
          c=$4; letter=substr(letters,c,1);a[$3]=0;for (x in a) {o=a[x];a[x]=a[x]+1; printf "\033[%s;%sH\033[2;32m%s",o,x,letter;
          printf "\033[%s;%sH\033[1;37m%s\033[0;0H",a[x],x,letter;if (a[x] >= $1) { a[x]=0; } }
      }'
  }