BACKSPINDLE

One Tape Runs Both Ways. BACKSPINDLE is an original portrait-first programming puzzle about arranging physical two-faced command plates. The old mill reads every FRONT face from left to right while Morrow travels outbound. At the heart core, courier and spindle turn around; the same plates are read BACK-first from right to left. A proof succeeds only when one finite tape reaches the core and returns Morrow to the dock.