Ancestor A2

This self-reproducing program works in a similar fashion to ancestor A1. The difference is that it explicitly searches for its beginning and end positions by looking for appropriate binding sites, rather than assuming that copying should start from memory address zero and continue until execution of the instruction mov_ic sets the flag. The program listing is as follows:

1-2	101100111000		Start marked with a specific binding pattern
3	et_collect
4	et_collect
5	nwm_clear
6	adrb
7	nop_10
8	nop_11		Search for binding pattern
9	nop_00		at start of program
10	nop_11
11	nop_10
12	nop_00
13	push_a
14	pop_c
15	et_collect
16	dec_c
17	dec_c
18	dec_c
19	dec_c		We now have to subtract the
20	dec_c		length of the binding pattern
21	dec_c		(12 bits) to get the address
22	dec_c		of the actual start of the
23	dec_c		program
24	dec_c
25	dec_c
26	dec_c
27	dec_c
28	push_c
29	pop_a
30	swap_ab
31	et_collect
32	adrf
33	nop_01
34	nop_00		Search for binding pattern
35	nop_11		at end of program
36	nop_00
37	nop_01
38	nop_11
39	swap_ab
40	set_jmp
41	et_collect
42	et_collect
43	clr_f
44	mov_ic
45	push_c
46	swap_cd
47	push_c
48	swap_ab
49	sub_ab
50	swap_ab
51	pop_c
52	swap_cd
53	pop_c
54	if_not_fl
55	nwm_write
56	if_fl
57	clr_jmp
58	jmp
59	et_collect
60	reg_create
61	nop_00
62	nop_10
63	nop_11
64	nop_00
65	nop_11
66	nop_10
67	nop_00
68	nwm_divide
69	stop
70-71	010011000111		End marked with a specific binding pattern
promoter	101100111000