1.3.1 - Bugfix for 261, 461, 861
1.3.0 introduced a regression that prevented compiling any sketch for the x61 boards with Timer 1 Clock Source set to CPU (default). This corrects that bug.
1.3.0 introduced a regression that prevented compiling any sketch for the x61 boards with Timer 1 Clock Source set to CPU (default). This corrects that bug.