correspondence between writhe convention knot files (with underscores, 0_1, 3_1, 4_1, 5_1, 5_2 ...)
and KnotPlot convention (with periods, 0.1, 3.1, 4.1, 5.1, 5.2 ...) is:


0_1 same
3_1 same
4_1 same
5_1 same
5_2 same
6_1 same
6_2 same
6_3 same
7_1 same
7_2 same
7_3 flipped
7_4 flipped
7_5 same
7_6 same
7_7 flipped
8_1 same
8_2 same
8_3 same
8_4 same
8_5 flipped
8_6 same
8_7 flipped
8_8 flipped
8_9 same
8_10 flipped
8_11 same
8_12 same
8_13 flipped
8_14 same
8_15 same
8_16 same
8_17 same
8_18 same
8_19 flipped
8_20 same
8_21 same
