role tints
(untick to see the raw cells, white = 1 and black = 0, exactly as the diagram renderer drew them; browser zoom keeps everything sharp)
Tints show what each stretch of cells is (parsed from that row); under them is the raw tape: light = 1, dark = 0; green = head.
(10)(10)… run at the left end
marker 11001
tail (10)…(10)1
pair: its (10)-run
pair: its (01)-run
digit block: 0001 = 1, 0010 = 0
Magnified: cells -23..6 of rows 9,515 and 10,419 (red box below). One count-down step touches pair 2:
step 9,515
counter 4
(10)-run, pair 2
(01)-run, q = 8
0010 = 0
pair 3 →
1
0
1
0
1
0
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
0
1
0
1
0
1
0
step 10,419
counter 3
(10)-run, pair 2
(01)-run, q = 7
0001 = 1
pair 3 →
1
0
1
0
1
0
1
0
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
0
0
1
1
0
1
0
its (10)|(01) border moved
2 cells right (q 8 → 7);
its digit block flipped
0010 → 0001 in place.
Pairs 1 and 3 were touched
too (outside this box).
Every cell, one row per count-down step; time runs down.
old (10)|(01) border, carried across a re-pair band
old digit block (its middle), the same way
step
counter
pair 1 →
pair 2 →
4,610
2
re-paired
5,190
1
−1
5,646
0
−1
6,366
1
End: + tail
6,950
0
−1
pair 1 →
pair 2 →
pair 3 →
RE-PAIR ↓
8,319
6
re-paired
8,963
5
−1
9,515
4
−1
10,419
3
−1
11,099
2
−1
11,999
1
−1
12,807
0
−1
13,983
3
End: pair 3 → tail
14,919
2
−1
16,075
1
−1
17,139
0
−1
pair 1 →
pair 2 →
pair 3 →
RE-PAIR ↓
19,436
6
re-paired
20,416
5
−1
21,208
4
−1
22,512
3
−1
23,432
2
−1
24,668
1
−1
← cells -152..47, 1 cell = 3 px. The (10)-run at the left end runs past the left edge on later rows (it grows 8 cells per row).