Paperboy (USA)

Paperboy (USA) is on a CNROM board with 32,768 bytes of program. A crawl of 400 steps from power-on kept 17 paths that found new code. Played back over 17,317 frames, they executed 4,799 bytes of it, 15 percent.

What the rules named

The 138 routines the runs entered

Every place the game's code was entered, by a call, an interrupt or a jump through a table. The ones a rule named come first, with what the rule saw.

at	entered by	times	what it is, and the evidence
$80EA	a call	12,444	The poll: port $4016, reads a frame 11, strobes a frame 4 The random byte: frames it ran in 5,062, bytes $0000, rotates 1, exclusive-ors 1
$8006	each frame (NMI)	6,766	The game inside the interrupt: frames it ran in 6,766, frames in all 6,817, the spin is at $80A1 The scroll writer: frames it ran in 6,766, writes in the blank 13,068
$853E	a call	6,551	The palette writers: frames it ran in 6,551, writes 586 The picture writer: frames it ran in 6,551, writes 3,568, in the blank 2,836, while drawing 732
$839E	a call	6,542	Where two things are compared: instructions 1, pairs of bytes 65, bytes in all 13, times compared 59,079, X positions at $0019,$001A,$001B,$001C,$001D,$001E,$001F,$0020,$0021,$0022,$0023,$0024 The sprite writers: frames it ran in 6,551, writes to the sprite page 720,675
$9C26	a call	2,457	The jump engine: tables 1, jumps through them 1,221
$98C8	a call	1,632	The jump engine: tables 4, jumps through them 485
$8706	a call	681	The jump engine: tables 11, jumps through them 279
$8722	a call	554	The jump engine: tables 8, jumps through them 475
$80A4	a call	58	The bank switch: writes 116, in the blank 0, while drawing 116
$8048	power-on	17	The sound driver: frames it ran in 6,594, writes 51
$80B3	a call	6	The jump engine: tables 1, jumps through them 6
$81F0	a call	74,532
$86BE	a call	27,311
$94FC	a table	15,284
$81B6	a call	9,098
$867E	a call	6,551
$8151	a call	6,203
$85C4	a call	3,600
$834D	a call	2,845
$A4CD	a call	2,487
$84F3	a call	2,469
$8044	a call	2,465
$8DB6	a table	2,465
$8F86	a call	2,457
$9B65	a table	2,457
$9F44	a table	2,457
$9FA4	a call	2,457
$9FB6	a call	2,457
$A462	a call	2,457
$9BE0	a call	2,456
$88A4	a table	2,414
$832B	a call	2,308
$8DC8	a call	2,239
$8FD6	a call	2,081
$861A	a call	1,617
$A4E2	a call	1,276
$9C1C	a call	1,228
$908B	a table	1,084
$872F	a call	794
$817A	a call	780
$818B	a call	780
$865E	a call	720
$8618	a call	690
$A69B	a table	582
$862B	a call	563
$864F	a call	562
$84EA	a call	524
$9698	a call	476
$81AA	a call	457
$9899	a table	431
$8E3C	a call	418
$98A4	a table	412
$98B2	a table	407
$98BD	a table	382
$86CC	a call	244
$A61D	a table	189
$A993	a table	177
$8290	a call	163
$8505	a call	162
$8530	a call	162
$8883	a table	161
$A87C	a table	132
$A90E	a table	130
$9AB2	a table	126
$82D9	a call	120
$8678	a call	112
$863A	a call	109
$860F	a call	102
$8643	a call	90
$8261	a call	88
$82B8	a call	88
$8244	a call	76
$A683	a table	67
$8A0A	a call	66
$8A59	a call	66
$8A70	a call	66
$8A76	a call	66
$8A80	a call	66
$9E98	a call	66
$A512	a call	66
$A522	a call	66
$9494	a table	62
$94F0	a table	54
$9E50	a table	48
$825C	a call	40
$811A	a call	39
$86C1	a call	36
$866F	a call	34
$8790	a table	30
$9652	a call	28
$8716	a call	26
$A5E1	a table	24
$A7BA	a table	24
$A605	a table	21
$986E	a table	19
$8629	a call	18
$864D	a call	18
$9E62	a table	18
$813E	a call	17
$8754	a table	17
$8785	a table	17
$8868	a table	17
$A4ED	a call	17
$A50B	a call	17
$95CB	a call	14
$821D	a call	10
$8928	a table	10
$89DC	a call	10
$9D37	a call	10
$9EF8	a call	10
$9B50	a table	8
$9BDE	a call	8
$9F31	a table	8
$A7C9	a call	8
$A805	a table	8
$A897	a table	8
$A929	a table	8
$86D5	a call	5
$9159	a call	5
$91B1	a call	5
$9235	a call	5
$9486	a call	5
$A7B0	a table	4
$88FB	a table	3
$9481	a call	3
$9A84	a table	3
$9F24	a call	3
$A58D	a table	3
$A5B2	a table	3
$8917	a table	2
$9AC4	a table	2
$852A	a call	1
$879B	a table	1
$891C	a table	1
$8A8B	a call	1
$9AA1	a table	1
$9E43	a table	1
$A40A	a call	1

Where it waits

Loops a rule named that sit inside a routine and are not themselves a place the code is entered.

at	what it is, and the evidence
$80A1	The idle spin: turns 48,914,261, turns a frame 7,175

The memory its routines share

689 bytes of memory were written by one routine and read by another, and 51 places were reached through an index, which is what a table or a set of object slots in memory looks like.

Reaches through an index: those that hold positions, then the longest

from	bytes reached	instructions	positions it holds
$000D	25	12	13 across
$0200	253	2
$0300	180	8
$0301	179	4
$0201	157	1
$0202	157	1
$0203	157	1
$0302	153	2
$0773	80	1
$0535	62	3
$05CD	44	6
$058B	44	1

What travels with a position

Arrays that at least two routines step through together with an array of positions, across the same range. That is what a table of the things on the screen looks like in memory: one array for each property, one slot for each thing. We can say which arrays hold positions, which of the others get added into them, which is what a speed does, and which pick the way through a jump table, which is what a state or a kind does. What the rest hold is not named yet.

slots	arrays	routines	positions across	positions down	added into them	choosing a jump	travelling with them
25	4	11	$000D				$0026, $003F, $0058

The 24 busiest shared bytes

byte	reads and writes	routines writing	routines reading
$0000	574,733	6	6
$0094	243,237	3	3
$009D	227,463	3	6
$009E	227,463	6	6
$0095	168,705	3	3
$0450	154,956	2	3
$0002	148,618	6	6
$0001	136,277	6	6
$0097	110,421	2	1
$0451	67,071	4	5
$0098	63,949	1	6
$0005	52,218	2	6
$0006	31,399	4	6
$00B1	24,654	2	2
$0007	21,897	4	6
$0090	20,280	1	2
$0400	18,814	2	6
$0500	18,463	6	6
$04FF	18,229	6	6
$04FB	17,599	6	6
$0519	17,388	5	6
$04FA	16,889	6	6
$0300	16,788	5	6
$041F	16,656	6	6

This page shows none of the game's bytes. The listing these figures were read from stays with the cartridge.

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