Six pages built by MAKE_TABLES at every new game: every byte value with its bits reversed, then shifted right two, four and six places across two bytes. Page $F2 holds the part that stays in a byte for a shift of two and $F3 the bits that fall out into the next; $F4 and $F5 the same for four, $F6 and $F7 for six. The tile drawing (PUT_TILE) reads a pair when it draws a building's other face (DRAW_PASS non-zero), mirrored; the sprites are mirrored in place instead (TURN_SPRITE). Zeros in the snapshot.